AIBU to not consider 21 a milestone birthday?

Yabu, its a huge milestone!

Never heard all of the song before. We only ever sang the 1st 5 lines. It must have been from the days when daughters were considered their father's property before marriage or turning 21.

Yes, but the key was just symbolic of a key to your family home, which you'd get in reality as soon as you needed it. I never got one at any age because we had a key hidden in the garden...

Because it used to be the age of majority. That's going back to my parents' generation though so grandparents to people turning 21 now. Time to forget it.

I'm a decade younger than you OP and 21 was very much treated as a milestone birthday by my family. As were 16 and 18 but 21 is when they were the most generous with gifts.

I didn't have a party though because a) I didn't want one and b) my closest friends were all at different unis by then. I did have a small party with 6 school friends at 18. Not because I wanted to drink though as I'm tee-total.

I don't think a party is what makes a milestone birthday or not. It's OK for some people to celebrate 21 and other people not! Why does it matter?!

I celebrated 18 at home because, as you say, it’s when you legally become an adult and can do more things. My parents said I could choose one of the two. However I was at university for 21 and we had a big party there, so I celebrated both as significant in different ways.
Edit: for context, I’m 61 and DD (30) did the same

Traditionally it was THE milestone birthday but it isn't in the UK anymore. I went to a few fancy 21sts in the 90s/2000s but haven't heard of them being a thing since. Nowadays the milestones just seem to be 18, 40, 50, 60, 75, 80, 100. Although I'd have thought every birthday is a milestone from 80 😅

Both 18 and 21 are recognised as significant birthdays in my family and my AC had special gifts on those dates and DGC will all get treated the same. It’s a personal thing I guess, what suits one family won’t necessarily be a great fit for another.

In my area (south east) it’s always been a milestone, although not everyone chooses to celebrate it. I had a big party for my 21st in the early 90s but some of my friends didn’t want a party so I think we had a weekend away in a cotttage, somewhere like the Cotswolds.

It was years ago - we used to get keys and things. Do they even sell them anymore? Not so much now. My son had a party but he likes parties. 18 is more of a milestone. What use is a tankard with 21 on it really?

Of course it is; it always has been. Obviously it's up to the individual if / how they want to celebrate.

I'm 52. My 18th was a big deal but aside from lots of cards saying 21 it was no different to my 20th or 22nd. None of my friends had 21st parties or made a big thing of it either. 18 was definitely regarded as the important one.

21st was more of a thing back in my parents day - key of the door and all that.

Definitely a milestone birthday. And has been for as long as I remember.

Many moons ago I worked for Clinton cards. Our milestones section was literally 16, 18, 21, 30 and onwards in 10s.

21 being a milestone goes back 100s years

No. I didn't do anything for mine 40 years ago and DD considered he graduation to be more important than her 21st which was 3 weeks earlier.

I went out on the lash with my mates for my 21st. I would have hated going out for a family meal and being centre of attention whilst everyone around the table sang happy bloody birthday to me - so cringy 🙄

South Wales here, was a big thing when I celebrated mine (21 years ago I've just realised!) and I was at DPs nieces 21st a couple of weekends ago, that was a big party (hired out a rugby club) so still a big thing amongst that age group now

My DD is 21 next month.

Yes, it is a milestone.

She is not having a party but I am taking her away for a few days (Lake District)

I will do the same for my son when is 21 too - possibly different location ?

16 and 18 were celebrations too.

Or maybe it's just the case that all humans are different and whilst some people do things, others may not.

Just because your DD and her friends don't consider it a milestone birthday, clearly others do.

Why does it have to be that what is correct for one person is 100% the case for everyone else?

FWIW I'm 40 and celebrated my 21st with a big birthday party, as did everyone I know.

It wasn´t to me, and I was 21 in 1995. My gran and aunts treated me to a posh lunch out, of which I have a huge photo and gave me cards with a key on and a lovely gold locket.
I treated it as a normal birthday as to me 18 had been the landmark. But then, I was brought up in Spain, where 21 isn´t a thing.

Why is it significant?

18 was the milstone birthday for me and my friends and my sons.

At 21 we/they were away at Uni so celebrated with friends but didn't have big family parties.

It's very culturally specific indeed - it's only a significant birthday in a small number of (English speaking) countries, and outside the USA where it's drinking age in most (but not all) states, it's only a milestone for historical reasons.

Surely it should be 25 (pre frontal cortex maturity, though very approximate and individual and arguably a couple of years later for men on average) ...

I guess 21 is the minimum age to rent a car with many rental car companies, but it's not significant for much else! Even for that there's a surcharge for under 25s (my adult child, who has driven tens of thousands of km in four countries in the EU and has a car through work which he has to drive in a very busy city centre between appointments, was most annoyed to discover that in practical terms renting a car in the UK is ruled out for under 25s).

Yeah it's just for the US when you can drink.

I remember the 'key to the door' cards from the 80s. It seemed like an old fashioned concept even then. Maybe in the mid century quite a few people actually did buy their first properties at that age? As surely you'd have a key to the family home long before that?

The only thing that really happens at 21 is a lot of kids might graduate uni. But that would be celebrated seperately.

I think it's less regional and more life stage related. If you go to university straight from school on a standard 3 year degree then 21 is also significant for being when you finish education and complete another significant milestone. If you've been working for 3 years already or on a longer degree or started later so still studying I imagine it would seem less significant.

I'm in my 60s but I seem to remember more fuss being made for my 21st than my 18th. I didn't have a party for either but the whole family went out for a meal to celebrate my 21st.

We celebrated DDs 18th and 21st. I think for her 18th we paid for her to take all her friends out for a meal. For her 21st she was away at University so DH and I went over for the weekend and we all three stayed in a swanky hotel in the city centre and had a meal at a very nice restaurant. She celebrated separately with her friends.