A related question, piggybacking on the many 29th birthdays comment -
At what age, if any, did you look forward to being older, or being able to say you were, and when younger?
Answer with identified gender shared if comfortable doing so please.
My WAG is that more men will state somewhere late 30s and women late 20s. Societal messaging of when our “primes” are.
OTOH some of us may still be waiting to hit our primes … 
I had an epiphany of sorts on my 17th birthday. While contemplating my navel (not really), I made a conscious effort to imagine it being my 40th birthday. I tried hard to mind-meld with my future self (though I knew that was impossible). I kind of of succeeded. I really felt, for a while, that I was 40 years old.
The downside is that it wasn’t a pleasant experience. I thought, nah, 40 sucks, I’ll stick with being 17.
But now, of course, I’d love to be 40.
I’m 43, probably feel about 30, and look early 30s. And not just people being complimentary…just a few months ago a colleague bet actual money that he was older than me, and turned out to be over 10 years younger. Easy money </john conner>
My body is trying to politely inform me of the truth though. I’ve started to get new pains and cramps, and when I recently tried to see if I could still do kip ups…yeah not even close. I’m slim but I just don’t have the speed or flexibility any more.
I’m 58, and don’t feel quite that old. I’ve got grey in my hair, and my beard has been almost completely grey for a decade. I’ve been running since I was a teenager, so my legs have a lot of miles on them. My students tell me that my hair looks old but my face doesn’t. If I had to pick a number, I’d say I feel 10 years younger.
Interesting question, and very young for me when I think about it. I can remember being hesitant to mention my age even when I was 26, say, because I still had friends and joined activities that included people still doing their undergrad degree, whereas 26 felt close to the dreaded 30.
The only time I can say I didn’t think of my age as any kind of an issue, the way a rich man doesn’t think of money as an issue, was about 20-24.
ETA: male
I heard a talk about this last week on the always wonderful “Brian Lehrer Show” (WNYC-FM), and the guest was exactly like me: someone in their early-to-mid 50s who subliminally thought of themself as someone in their mid-to-late 30s. So, a 15-year difference, give or take.
I’m pretty sure my mom reached her mental sixties well before her 40th birthday, too.
Continually discovering how little I know helps keep me feeling decades younger than my 69 years.
I’m not sure I ever did look forward to being older when I was young. Not in a definite sense of “man, I can’t wait until I’m ___”. I know I used to think about turning 32 in the year 2000 and thinking that was unimaginably old 
. But I think the only time I have ever even partially wished I was older is when I was impatiently approaching minimum retirement age at my job (which I’ve fairly recently passed). In that case I just wanted to hit that chronological mark for a little psychological peace of mind. I didn’t really want to be older.
When did I start mentally thinking I was younger than I was? I think you’re correct in that I think it was in my thirties. However not all that strongly. At the time circumstances had resulted in many of my friends and co-workers being either several years older or several years younger than I was. Very few near my age and that was when I was young enough where that made some difference - hanging out with people in their twenties made me feel a little older, hanging out with people in their forties, younger. I think it really kicked in in my own forties when that effect lessened.
I should say physically, I DO feel my age. Sadly so at times 
.
I’m realizing that I have a very difficult time really remembering what I was like and how I thought at other ages, which may be a factor in my not being able to pinpoint how old I feel mentally.
What I do know is that sometime in the past five years, during the transition from late 50’s to early 60’s, I started to really feel older. My body doesn’t do the things it used to - some physical activities I used to do with little effort are now not just difficult, they’re impossible (I should reread the “Why don’t you lift weights?” thread for inspiration to see if I can change that).
But the thing I find more disturbing is that it’s become noticeably more difficult for me to learn new things, and it’s not just a preference for the familiar. Fifteen years ago, our school system changed student information software. I volunteered to be on the employee committee to evaluate new programs, I learned how to use the new system, and I became the de facto trainer for not only my school but for information clerks across the district. Nowadays I’m dreading getting a much-needed new home computer just because I’ll need to learn how to use the latest version of Windows. I plan to keep pushing myself, but it bothers me.
Another related spin - do you feel you are physically and/or mentally older or younger than others your chronological age, maybe especially those like classmates and friends you knew from childhood? If you had your telomeres tested for biological age what do you think the results would be like, relative to your chronological age?
It’s weird being the same age as old people.
I’m a little embarrassed to discuss my telomeres in mixed company, but I believe they are as long and firm as anyone else’s my age, if not more-so.
I feel old in body, but not spirit. I still maintain my youthful outlook, and humor more than other’s I encounter my age. Sure, my kids, and their friends, and their friend’s friends, and other young people I come across, treat me like an old fogey, but, they don’t fool me. I know, deep down, they think I’m a pretty groovy hepcat.
This really hit home. Learning new technologies during my last decade of work became increasingly difficult. I’ll probably hang on to my existing pc until it’s no longer able to function online.
I never really thought about this until quite recently. Just before the pandemic I went on a solo walkabout in several continents for a few months, and it didn’t occur to me that I might be viewed as an ‘elderly’ person.
Of course, I followed the usual guidelines: walk firmly and purposefully as if you know exactly where you’re going.
But now I find myself almost 75. And my first grandchild has just been born.
I am starting to feel… a bit, old. I don’t like it.
The article (and others like it) mention that moment when your real age suddenly is made clear.
For me, it was last May, at a college reunion, with two classmates. (We’re all our 50s now). One of the friends’ son is now a student there. We stopped by the son’s pad (his friends were there, too), and smoked a bong together. It all felt so collegial (but man, pot’s gotten stronger since thirty years ago!), until the kid’s friend said something like, “wow, it’s so cool your dad and his friends are into this! I didn’t think people like that were!”
Ouch.
I turned 70 last year, but I occasionally have trouble believing I’m that old. (Except for occasionally when I try to do something that I never used to have trouble doing.)
A few days ago I was in the hospital having a minor cardiac procedure done. Since I live alone they decided to keep me overnight “just to be on the safe side” in case I had a delayed reaction. In the morning the night nurse mentioned that she had been surprised when she looked at my chart and saw my age. She had thought I was only in my 50s. So I guess I don’t necessarily look my age.
I’m 61 but look and feel younger. I imagine myself in my 30s and probably look like I’m in my mid to late 40s. I don’t physically feel like I’m in my 60s. I have no aches or pains, I don’t take any meds, and I can do everything physically that I want to do. I just can’t look at a selfie (I hear ya SuntanLotion!!).
My head simultaneously thinks that I’m 7, that I’m 27, and that I’m 71.
The last of those is what gets written down on forms, this year. Or, at any rate, through part of this year.
Slightly off-topic, but I think it’s great that the Straight Dope membership, despite having a large proportion of seniors, is very open-minded, keen to learn new ideas and technologies, and remains largely immune to the silly culture war talking points of the day.
Almost fills ya with hope…
I feel pretty young. I don’t have a problematic mate or any children or any bills. I have a job I like, I keep a good diet, and I work out almost every day. I guess those are the reasons why.