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15 year-old know it all son

308 replies

Spiritedlight · 24/02/2026 10:00

Hi everyone

I would like to have thoughts on how to handle/progress with son. He's 15, smart, lovely, very opinionated, completely resistant to being told anything and thinks he knows it all.

For example, a discussion about astrology/space etc - whilst DH is very knowledgable, DS will disagree with everything DH says, and quote, frankly, bollocks a lot of the time.

If we talk to him about the school's recommendations for self-study in Year 10 - which I know he's not doing, because I know what they expect - e.g., 2 x 30 mins of going over triple science lessons a week -he will completely tractor over the discussion with comments like, "I'm doing it through homework, it's about quality not quantity (he does the bare minimum), my grades are very good (not as good as he thinks) etc etc". Everything gets brushed off, diminished, he knows best. Always.

It's the oddest, most annoying thing. I've tried to talk to him about it but I don't get anywhere - except that he thinks we are telling him off, which suggests to me this is a defence mechanism. And we are really not telling him off in those moments, we're trying to open up conversation and be supportive about these school years.

I'm worried about his grades and how he's just going to not fulfil his potential. DH thinks let him get on with it and fail mocks etc, so he'll see for himself. But I don't know what to do.

OP posts:
sellersvin · 24/02/2026 14:38

Muffinmam · 24/02/2026 13:22

He doesn’t sound smart - he sounds narcissistic.

An intelligent person doesn’t argue about things they know nothing about.

My brother was/is incredibly intelligent. He was gifted as a child and coasted through school without any effort.

He argued about things he knew about and as an adult he is extremely well read and now works in a STEM field.

The problem with gifted children is they can burn out after highschool. They grow up knowing they were the smartest in their entire school and never had to try. At University they are often not the smartest and need to actually show up to lectures or they will fail.

There’s also the possibility that a person can be so intelligent they can feel ostracised from their peers and suffer terrible mental health.

I don’t think your son is at any risk of either of the above scenarios.

I suggest you encourage your son to pursue a trade if his grades are bad. Also, if he’s arguing about things he has no knowledge of he will completely fail at University as no one will put up with his BS.

As a parent it is your responsibility to prepare your children for society’s expectations and part of that is social intercourse. Without social skills he will fail to establish a social network at University or in any workplace which will very much limit his career options.

ASD?

RideMeSidewaysWasAnother1 · 24/02/2026 14:34

No words of wisdom OP but I'm in the trenches with you. Almost 14year old here and he was shocked the other day that we knew what the word cringe meant 🤣.

Maray1967 · 24/02/2026 14:26

I’ve been through this twice. My advice is to breathe deeply and step back.

That is also my advice as an HE first year course lead. The students who struggle the most, aside from those with very serious personal circumstances, are the ones whose parents dragged them through GCSEs and A-Levels and who have no self discipline. Now is the perfect time for him to
learn some lessons. If he under performs in the mocks it should provide a wake up call.

Dollymylove · 24/02/2026 14:25

He sounds like most teenage boys, to be honest 😅

Franjipanl8r · 24/02/2026 14:18

Do you actively listen to what he says or just always give contrary opinions? My parents are incapable of just saying “yes dear” or “I hear what you’re saying” or “oh that sound difficult”, all they do it just tell their own completely irrelevant stories and throw in constructive criticisms. It’s infuriating and often results in just constantly trying to reaffirm my opinions.

NamingNoNames · 24/02/2026 14:13

RobinEllacotStrike · 24/02/2026 14:12

what a pointless thing to say

What a pointless thing to say.

RobinEllacotStrike · 24/02/2026 14:12

NamingNoNames · 24/02/2026 14:03

@RobinEllacotStrike , that quote has already been posted on page 2.

what a pointless thing to say

LardyCakeLover · 24/02/2026 14:11

frozendaisy · 24/02/2026 10:13

Yep let him fail his mocks he will have to turn it around if he wants to

at least then you will have lower marks in black and white to suggest perhaps more effort and the teacher’s advice could be listened to

We took this approach regarding failing mocks. Unfortunately, COVID hit and our sons A level results were largely based on the mock results. Had to spend another year at college to re-sit.

Simplesbest · 24/02/2026 14:10

My 15 yo went through this. I got very bored very quickly especially when he thought he was the cleverest person in the house yet was failing all his exams dismally. I just regularly burst his bubble in the end. Stuck to facts and kept bringing it back to what he had actually achieved so far in his life vs what he imagined he had achieved. He passed through it and we laugh about it now but he was so far up his own arse it was embarrassing.

SomersetBrie · 24/02/2026 14:09

DysmalRadius · 24/02/2026 14:08

I have also pointed out, to some of the more emphatic teens that I have encountered, that it's easy to know everything with the internet in your pocket. When my brain was at its most plastic, you had much more limited access to information about anything.

If I wanted to know if frogs can cough when I was 14, I had to hope that there would be a documentary on frogs that covered it sometime when I was at home in the next few months. Now, you can have the world's leading frog expert telling you everything you want to know in seconds! 😁

The world's leading frog expert usually being a teenage boy 😁

DysmalRadius · 24/02/2026 14:08

I have also pointed out, to some of the more emphatic teens that I have encountered, that it's easy to know everything with the internet in your pocket. When my brain was at its most plastic, you had much more limited access to information about anything.

If I wanted to know if frogs can cough when I was 14, I had to hope that there would be a documentary on frogs that covered it sometime when I was at home in the next few months. Now, you can have the world's leading frog expert telling you everything you want to know in seconds! 😁

Violinist64 · 24/02/2026 14:05

This is about the worst stage with teenage boys. Girls tend to to be at their worst in their early teens when their hormones run riot but it seems to mostly take the form of tears, drama and flouncing with them. Boys are at their worst in the mid-teens, as you are experiencing. The know-it-all phase, accompanied with a loud voice and deafness to any reasoned argument is classic and extremely wearing. The good news is that they do outgrow this phase. When one of my sons was seventeen, he was all set to join the communist party. My mother was horrified but I knew he would outgrow it - l called him our resident red. He was not bothered about the USA banning anyone with communist leanings from entering the country but when he found out that Singapore, where we have some close family members, takes an equally dim view of communism, he felt that family came first and his principles became watered down out of necessity.

ApplebyArrows · 24/02/2026 14:04

To be honest I think think the school are being completely unrealistic in requiring this sort of self-study at this age. Directed homework tasks are generally educationally effective; "spend an hour reading your notes" is not.

NamingNoNames · 24/02/2026 14:03

@RobinEllacotStrike , that quote has already been posted on page 2.

Ormally · 24/02/2026 14:02

15 year olds don't want to be 'edited' by you (and, to an extent, vice-versa too).
They recognise the importance of being 'edited' by teachers and information, but resent it a lot of the time. At the right times, it will light a fire of determination and enthusiasm rather than heart sink and grind. I suspect this is the early stages of a few years of it.

Haven't really trodden a consistent path with it, but instead of having a struggle of wills and how right you are or not, some phrases have been more successful: "Ok, but you do see why I keep trying to guide you into doing this?" is one. "Do you think (he) is really being respectful by saying that?" was another, about a character being arsey in a film. Not always a great result, but some result.

RobinEllacotStrike · 24/02/2026 14:01

Just want to share this Mark Twain quote with you OP - hang in there:

“When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years.”
― Mark Twain

My know it all is now 18 & things are getting much better

Lemonade2011 · 24/02/2026 13:52

Ah the joy of teenage boys, I have 2 older boys (24 & 21) who also thought they knew it all and just wanted to do their own thing a not listen. It was a trying time!! ( it does pass) and currently have a 15 year old - 16 soon and a 14 year old who in 15 in June. So your post resonates. My son is lovely but he can just be a moody arrogant little so and so at times.

I don’t do the harsh tone as soon as you do they’ve switched off. We just explain you treat people with respect even if you think you do ‘know it all’ and we are doing the exams this year and passing means choice for s5 and 6 so he needs to step it up. It’s hard work though!!! They can be so arsey sometimes it’s hard to not get angry.

my older 2 are doing well though so I hold on to the fact that it will all work out in the end….

Franpie · 24/02/2026 13:42

There is absolutely nothing that my teenagers don’t know. Me and DH on the other hand are old and stupid and don’t know anything about anything.

I just silently repeat the mantra in my head “this too shall pass”.

SomersetBrie · 24/02/2026 13:41

Muffinmam · 24/02/2026 13:22

He doesn’t sound smart - he sounds narcissistic.

An intelligent person doesn’t argue about things they know nothing about.

My brother was/is incredibly intelligent. He was gifted as a child and coasted through school without any effort.

He argued about things he knew about and as an adult he is extremely well read and now works in a STEM field.

The problem with gifted children is they can burn out after highschool. They grow up knowing they were the smartest in their entire school and never had to try. At University they are often not the smartest and need to actually show up to lectures or they will fail.

There’s also the possibility that a person can be so intelligent they can feel ostracised from their peers and suffer terrible mental health.

I don’t think your son is at any risk of either of the above scenarios.

I suggest you encourage your son to pursue a trade if his grades are bad. Also, if he’s arguing about things he has no knowledge of he will completely fail at University as no one will put up with his BS.

As a parent it is your responsibility to prepare your children for society’s expectations and part of that is social intercourse. Without social skills he will fail to establish a social network at University or in any workplace which will very much limit his career options.

I'm guessing you've never meet a teenager?

lizzielizard · 24/02/2026 13:40

“When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years.”
― Mark Twain

LeedsLoiner · 24/02/2026 13:40

Toddlerteaplease · 24/02/2026 10:11

A friends son is exactly the same. His parents just laughed it off and said he was going to be a politician, but I found annoying and rude.

Sounds like he's perfectly qualified !

HelpMeUnpickThis · 24/02/2026 13:39

Spiritedlight · 24/02/2026 13:04

Thank you for the advice and the feedback. It's sobering re: harsh tone - that said, I am VERY aware of it, he knows I'm aware of it, and it's countered by a ton of praise, love and unabashed pride in who he is. But my own traumas and upbringing certainly contributed to my directness and sharpness - it's no excuse, but it's something I am very aware of and constantly try to work on.

Thank you for the important reminder - my relationship with kids is of the utmost importance.

Hi @Spiritedlight

I am NOT trying to pick on you but please do whatever you can to sort out your own childhood / upbringing issues so that you don’t pass on the trauma to your son.

You say you are aware that your background affects how you speak / interact with your son. If so - then do something about it.

Don’t pass the trauma down.

pinkyredrose · 24/02/2026 13:38

CustardySergeant · 24/02/2026 12:57

Yes, she said so in her post at 10.22.

I missed it!

Spiritedlight · 24/02/2026 13:37

Muffinmam · 24/02/2026 13:22

He doesn’t sound smart - he sounds narcissistic.

An intelligent person doesn’t argue about things they know nothing about.

My brother was/is incredibly intelligent. He was gifted as a child and coasted through school without any effort.

He argued about things he knew about and as an adult he is extremely well read and now works in a STEM field.

The problem with gifted children is they can burn out after highschool. They grow up knowing they were the smartest in their entire school and never had to try. At University they are often not the smartest and need to actually show up to lectures or they will fail.

There’s also the possibility that a person can be so intelligent they can feel ostracised from their peers and suffer terrible mental health.

I don’t think your son is at any risk of either of the above scenarios.

I suggest you encourage your son to pursue a trade if his grades are bad. Also, if he’s arguing about things he has no knowledge of he will completely fail at University as no one will put up with his BS.

As a parent it is your responsibility to prepare your children for society’s expectations and part of that is social intercourse. Without social skills he will fail to establish a social network at University or in any workplace which will very much limit his career options.

With all due respect, that's a ridiculous jump. It is not narcissism. Being a “know-it-all” is a behaviour. Narcissism is a personality pattern. Nor is he gifted. And he has social skills; I'm talking strictly about his relationship with us.

OP posts:
Captcha4903 · 24/02/2026 13:29

I thought I knew everything at that age. I had never failed at anything...

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