I am in my late 30's now and I can feel things changing. There were a number of time periods I would pick as turning points:
Grade School, Middle School, and High School
I had good parents and good friends. No complaints... but I rarely reflect on these years. I remember the people and a few highlights, but I can't really tell you any stories. I feel like my life didn't really start until my college years.
20 to 26, Floundering Years
I finished college, but wasn't passionate about anything I studied. I got into a career because that was the next step, but it wasn't the future that I had always envisioned for myself. I made good friends at this time that I have kept/will keep the rest of my life. Best thing that happened to me during these years is I took on responsibility that forced me to buckle down, grit my teeth and get through it. There are countless times when I wanted to quit without other career prospects. That is the pattern most of my friends have taken over the past 15 years. Start a new job, burn out after 2-3 years, start over. Every time they start over, their life gets turned upside down and it is so turbulent for awhile that they never make any progress.
27 to 32, As Good As It Gets?
I felt invincible. Athletically, I was at peak performance. Strong, fast, incredible eye-hand coordination, and I felt as quick mentally as ever. I was super productive these years and could bang out any work tasks that came up without much trouble. Write a new 100 page manual? Take a team and manage 12 employees twice my age? No problem, I could take any any challenge and overcome.
33 to 37, Slow Decline
My physical prowess began its decline. It felt like trying to hold onto sand as it slips through your fingers. One way I would describe it, is that I occasionally felt "clumsy" for the first time ever? It was also around this time that alcohol started to give me hang-overs, hot-sauce would torch my asshole, my hair started to thin on top, and I could finally put on some weight if I didn't watch what I eat. I would occasionally make mistakes. I stopped having all the answers. Things at work might tax me mentally and I would stress tremendously. I also felt the regret of not settling down with a woman that would be my wife and mother to my children.
At 38, Present & Future
I am not scared of the future, but I am not overly optimistic either. I should have found a wife 10 years ago. I should have a kid that is going into the 5th grade. I am going to be in my 50's or 60's by the time I have a college-aged kid, if it happens at all. If they choose to wait later in life to start a family, I might never live to see my grandchildren. The more years that go by, the less likely is it to happen at all.
Mentally I am just not a quick as I was. Life gets significantly harder as more time goes on. Obviously we all know that our bodies break down the older we get. But mentally and personality wise I don't like what I am aging into. In my mid-20's to early 30's, I could engage on just about any topic. Politics, music, movies, shitty pop-culture, sports, and certainly anything in my industry of business. I actually feel dumber and less interesting today than 20 something'ish me. It is kind of pathetic but I guess that is life? Conversations are a chore, and I have new friendly acquaintances but no new real friends.
Looking Back...
I am grateful to younger me for a few decisions though. Financially, I am secure. Retiring at 50 will be a real option if I want to take it.
I opt'd into my employer's 401k matching plan since paycheck #1 with the maximum amount. I never used credit cards. The only money I spent, was money I had. If I wanted something, I saved and bought it with cash (even cars). I didn't knock up any girls and put a child-support-anchor around my neck. I was the first of my friends to buy a house and have them pay me rent. I realized how easy the money was, so I continued to buy and rent houses in 2006, 2011, 2014, 2016, 2017, 2018, and an apartment complex in 2019.
I guess I would recommend to any young person to have goals. Even if they aren't completely defined, have some ultimate goals with checkpoints along the way to get you there. Life goes by fast.