Stretch every day. Before you go to bed, and after you get up. 10 mins. It will change your life. Also, take a regular yoga class. Once a week, or once a month doesn't matter. Just start doing it NOW. Getting that internal knowledge of your body, how things work, how things feel, and the detailed knowledge of what is normal in your body, will become INCREDIBLY important as you age. I'm 50 now. Never had major injuries or surgeries, and have spent a large part of my life being not particularly fit. I have little knowledge of my body outside of what I drape it in... so when the doc asks, "Has it always been like this?" or "How has it changed?" I am completely powerless to tell her. And, I have learned stuff about how my body SHOULD have worked. Like that my wrists only have about 1/3 of the range of motion that most people's wrists have. If someone wants to pour some nuts into my palm, I have to cup both my palms together... I can't turn my hand so my palm is pointing directly up. So pour nuts in my palm, and they fall off the pinky-finger-side of my palm. If I had been stretching regularly, doing yoga, whatever, I would have known this was "weird" and was something I needed to focus on when stretching, to keep limber and protect my range of motion over the years. At 50, I may be able to recover my range of motion, and get back to everyone else's "normal". Maybe.
I have a large band that I use before my gym training to keep my shoulders warmed up - I do these dislocations methodically and the older powerlifting guys tried it once, only able to get their arms above their heads, couldn't go any further. Next week they all had a band of their own to work on their shoulder flexibility, it was adorable but also scary that they simply never noticed it until they tried that specific movement.
Good for you man. I’m stretching as I type on the floor. Running is great too. I’m 45 and feeling good because I run. I teach 8th grade math and got In my fastest 5k of the season this morning before my first day with students back. I didn’t take the time to stretch this morning though and wish I’d had. I expect I would have recovered faster. Thanks for mentioning the importance of stretching.