'Of course'

[badger2005]

Me: "Thank you"
Other person: "Of course!"

What does it mean? (And what does it say about the other person? Young? American?)

I've trained myself to say "You're welcome" or (when appropriate) "My pleasure" when I'm thanked, rather than downplaying what I did (e.g. "Oh no, it's not bother, I was going that way anyway" etc), as I think that the downplaying response is kind of a rejection of the relationship building move of giving and receiving. (I may be "over-thinking" this. Actually I need to start a separate thread about how much I hate the expression "over-thinking" and why. It's probably because I do a lot of it, and would like it just to be called "thinking"...).

Anyway, is "Of course" more like " Of course I would do this for you because you are important to me", or more like "Of course, I was doing this anyway, and you shouldn't really be thanking me - that's a misunderstanding of why I've done this and how I feel about you")?

American!
We were in Florida in Feb and almost every server (sic) said of course as a response to our thank you. I noted it at the time as a weird, illogical, new verbal habit.

I've never heard this.

I've only been hearing it recently and just from two people I think...

I've never heard of this, but I think it sounds awful! It doesn't make sense either. Saying "of course" when someone has thanked you sounds like you're saying " of course you must thank me, I've done something for you and I expect to be thanked".
I mostly say " my pleasure" or sometimes" you're welcome".

Yeah I agree it downplays the thanks for sure. In America we got a lot of ‘you’re fine’ or ‘you’re good’ 😵‍💫

”Thanks!”
”You’re fine”

….. I know I’m fine, but still, thanks for doing what you did for me 😅

Its just different cultures isn’t it.

So one person i hear it from is American, but the other is British and young, so I'm wondering if it's becoming a thing?

So, I guess it looks like it's become a thing.

It is very similar to the French ‘de rien’, it was nothing. I hear ‘no worries’ as a reply a lot as well. None of those replies bothers me, in particular, it is just evolving language.

American

I think it’s similar to when Germans say “natürlich”.

“Thanks for doing that!”
“Of course I would naturally do that thing for you as it’s no problem whatsoever”

I remember this crabby woman who came into a hotel I worked in once. She rudely demanded a pot of tea be brought to her in the lobby as there was a bit of a queue. I told her that would be no problem and I would just get it for her. This incensed her! Apparently “well it should be no problem, it’s your job!!”.

Been scared to say “no problem” ever since.

I would guess it means ‘it was just a matter of course’ so closer to your second interpretation.
I seem to remember reading something by an American from the war or 1930s complaining that the British said ‘thank you’ all the time and seemed to have no equivalent of ‘you’re welcome’ and if you said it they’d just be confused and say ‘thank you’ again.
‘No problem’ is probably worse.

American. I remember hearing it in the late 2000s on American TV programmes.

Thanks all! I decided to try it out, but my teenagers just laughed at me. Apparently it doesn't work if you mutter 'no problem', hesitate, and then blurt out 'OF COURSE' loudly when you remember your plan to try it out...
I'm going to give it another go though...