I wasn't going to post my age here, because I already did it in the original thread, but I like the idea of using Roman numerals, so my current age (not for long) is a nifty...

XXX

Is anyone here in his 30s or 40s sad, or sad sometimes, that the juvenile days are long gone?

I'm not.  I got through raising my son a few years ago, he will be 21 next month.  I'm single and now have opportunities to relive my juvenile days but with money and all the experience I've acquired.  I have a shit load to look forward to. I game harder now than I did when I was younger, play harder with the ladies, and about to enter early retirement in a couple of years which will be spent traveling, writing, and producing.  I plan to make the next 30 plus years amazing. Lock away your wives, sisters, aunts, grandmas, and mothers, because my Anaconda has a mind of its own and is always feeding.

It shows

I'm the same age as the United States of America, give or take a couple hundred years.

In my early 20s, I had a significant time dilation crisis. I was thinking where the heck the time went, and got majorly depressed, and kept thinking that time went way too fast. Some years later and I still feel the same way but I try to make the most of it, instead of worrying about it. When time is so precious to me, I can't be doing stuff that is a complete waste of time, like worrying about time.

25. It makes me feel like grown-up in most of intenet forums I use but here I feel young 

Sometimes, it's a trade off. More wise, but also less physically able. Definitely less risk taking as simply pulling my back can disable me for months. Gone are the days of diving down a mountain on a bike, crashing into a tree (not on purpose) and shrugging it off, scrapes gone the week after. Injuries take so much longer to heal now and some never fully heal anymore.

At some point you go from getting stronger to simply trying to maintain your current physical strength and endurance. I passed that point 5 years ago, now having to be more and more careful while weight lifting and no longer go on that many long distance cycling trips. Same for running, knees start hurting a lot sooner now. I miss going for a long run limited by getting tired instead of by knees giving up.

When I was younger I always thought about traveling the world when I was older (and have the money). I have the means now, but the desire to travel has waned. Not the curiosity, I'm currently using FS2020 and google maps to explore the world. However the memories of bad experiences with air travel, getting sick abroad, getting ripped off, and simply not feeling as energetic anymore, virtual tourism is fine.

I also miss not caring about tomorrow. Now I have kids and other responsibilities. No more all night playing games, sleep all day next day. No more raves until early next morning. Well I do still play games until late at night, but there's always the nagging feeling, you should go to bed. Pulling an all nighter really sucks at age 47.

However, on the much brighter side. No more depression, no more suicidal thoughts, no more loneliness, no more bullying, no more wondering whether I can afford to go to a movie, far less insecurities, mentally so much healthier than in my juvenile days. Trading physical health for mental health, good trade imo.

It's me, so prepare for a very stream-of-consciousness reply:

I'm 38 and have made a pretty good mess of my life, so yeah I miss the days before I did that a lot. I'm still single and childless, I live in poverty and work a worthless dead-end job and have no idea how I would ever qualify for anything better at this point. The truth is that I'm living pretty much the same way I did in my late teens and that makes me feel like a failure. I seriously fear that I'm going to be alone for the rest of my life and my age doesn't exactly reassure me in that regard. I live in a place where most people are older than me though, so I don't feel so ancient IRL as I do on gaming forums. So at least that.

What I've learned to do is to try and look for the good things in life. It's a choice and by no means an easy one most of the time for me. The perspective that keeps me going is that a moment of joy, like something that makes me laugh for example, makes a day worthwhile. That's the philosophy I've sought to adopt.

I wouldn't call myself wise because if I were wise, I'd probably be doing better at this stage of life. I would say that I've learned things though just by living. Like I see cyclical patterns to events where I didn't before and stuff. I also find that I tire a lot more easily both physically and mentally. Just live with a perpetual kind of exhaustion with the world and with life, which is ironic considering how rarely I've even ventured outside of the town where I was born. I feel like there's so much more to be explored and discovered out there, but I'm destined to just rot here forever. I'm ironically bored to the point of exasperation by the tedium, predictability, and slow-burn deterioration of my life yet increasingly lacking the energy to indulge my curiosities and learn new things. It's more and more tempting to just fall back on the things I already know I love and keep listening to the same songs forever, playing the same games over and over, watching the same movies over and over, and not want to explore new technologies and stuff (still have no mobile phone in 2021) and keep up with the Joneses because it's too exhausting to even think about. This is how people become closed-minded and it's more and more tempting to give into as I get older. I'm making a conscious choice to avoid giving into that impulse favoring laziness, but it's getting tougher not to because it's so much easier to settle for the familiar even though I'm sick of it.

Also, my reflexes are getting to be shit and I forget things way more easily than I used to.

All this said, conversely lots of things that got me really excited or angry when I was younger just don't anymore. I'm less idealistic and excitable than I used to be and accordingly more annoyed by outrage culture and also less blown around by fads. To put matters perhaps more firmly in perspective on that, you know how when you're ten, a five year old seems like they belong to a different generation? Or like how when you were 18, you might have seen a 13-year-old that same way, as like a generation apart from you? I still feel that way. Like someone who's five years younger than me, like a 33-year-old, is a naive, excitable kid in my mind even though they obviously aren't objectively. Most 33-year-olds are probably way more mature and accomplished and in touch with the times than I am in reality. I don't know why my brain still plays that same trick on me.

Taking the better of everything is really the wise thing to do, isn't it? I've lived with lots of difficulties in my life for the last seven or eight years but I never stopped myself to consider the good things I have and can do until very recently. Right now I think I've been living the most stable weeks of the last ten years of my life, and I wouldn't say I'm doing wonderfully, but now I finally have plans, I want to position at least for a year in my job, I want to return to school once the virus crisis is over, I want to buy a lot of stuff, and I just started with a new monitor, I think I can finally deal with my interpersonal problems with my family, and so much more. I used to say that I enjoyed suffering, but that gets you nowhere and only makes things worse. 

And about you being more out of touh with reality than most 33 year olds, I wouldn't be so sure. Everyone has their share of problems, and I can bet you that a lot of 30 somethings not only have financial troubles, but social and personal ones, too. Everyone at one point must say, "yeah, I think people around my age are doing better", when in reality you're just doing like everybody else, with subtle differences. We seem to live in the best times ever but at the same time it's not so easy. Additionally, it's never too late for anything. You at least have a job, and as little as it may be, it can mark the beginning of something else. Sometimes I feel like people have the impression that bouncing again in life takes a lot of time, not saying you do, but I say in a year you can make radical changes to your life, for the better, specifically.