Not too old yet, 45. But learned many things already because I did a lot of things. Hope to learn a lot more; let’s do this again in 10 years here. Anyway;

If you have enough money, stop trying to get more and live your life instead with your family and friends. Apparently it is really hard for people who gathered a few 100k/million (depending where you live) to just let it be and enjoy. Moreso (as I understand) in the US than in the EU. In the EU you hardly need money to begin with depending where you live and want to live; Where I live, all my neighbours live of around 500/mo. As a wfh software dev, 500 is literally a few hours work. And that would be me alone working from home; my wife does too... The always trying to get more and buy crap turns out, when you get older (and friends/family starting to die off/get ill) you understand it really does not matter at all. But then it might already be too late to correct it, even with all your cash. It is hilarious to me to read all these ‘time managed’, mostly Americans on here; every second of their day as efficiently managed as they can. And for what? Go outside, walk in a forest, talk to strangers; Running the same time managed wheel every day; that I find the real waste of time trapped in your own rat cage. I needed to grow older for this though to realise some of it; I never did the timemanagement thing (as I always believed it is sheer insanity; but I guess that is a matter of what you think counts as valuable; I enjoy walking in nature, I do not enjoy spending time in the gym efficiently and eating soylent to save a few hours in my day; those hours are valuably spent on thinking in the forest, chatting with friends in the sun on the square etc; then I use 4-5 hours to write code, which I already worked out in my head while walking; for backend and firmware coding, that is far more efficient than just ramming in as many chars as you can and then trying to run it; also something I learned as I got older; I am much faster in delivering than my young colleagues; not because I am smarter but experience and thinking shit through before just hammering it in and letting unittests tell it is wrong; I find that an actual utter waste of time) however I did miss important events I should not have missed because I was working for a few extra bucks. Events that will never repeat.

Ofcourse we are lucky to be able to work from home and people who do not want to move to a different/cheaper place obviously have less choices, but also that gets easier when getting older, at least in my experience. The city becomes less interesting; freedom and space more. With covid we saw here that indeed people are not that married to their cities and their cramped appartments: lot of houses sold that were empty for years; now suddenly they have almost no cost of living (even going to a restaurant for a complete meal and drinks costs 6 euros pp if you fancy that) and space to breath. So the money earned in the ratrace suddenly might get you well into retirement and then there are state pensions and hospitals are free anyway. Especially if you have a house or mortgage in the city, you can sell it and that’ll keep you good for 20-40 years if you don’t buy rubbish. Or you can rent it out and you are good basically forever. Not that I like that personally but I know many who did exactly that so they could retire at <40.

Physically; do fasting and weights; really helps energy levels and pushes back on loss of muscle mass which will happen when you get older. I notice that people who focus less on their wasteline and more on bulk make it far longer in a far more robust way. Skinny muscleless ex runners/cardios don’t do so well when going 80. Obviously do not get too fat, do not smoke/vape(although, ofcourse my entire village smokes 3-4 packs/day and the elderly are in their 80s/90s puffing away while sitting in the full sun for hours without sunscreen, but that is just, I guess, survivors bias), take care of your teeth and when you feel something weird anywhere, go to the doctor. People wait way too long, especially men.

Edit; a more depressing thing of getting older, for me, was seeing how incompetent, lazy and untrustworthy people are. We tolerate blatant lies from
ceo’s, cto’s and our colleagues almost every day. From small ones (I will work this weekend for this one time and then ‘my computer was broken but miraculously works again on monday’) to potentially company breaking lies by sales from vendors ‘yes this feature is done and delivered’; 2 weeks before beta; ‘oh did he say it was? no that is done somewhere in 2021 but we do not know when yet). I see it everywhere now; it was always there but it starts to really annoy me now.