I'm 43. I started noticeably slowing down and becoming more risk-averse in my mid 30's, after several repetitive ankle injuries made life a real fucking hassle. I remember being in my late teens and thinking I would NEVER stop skating for any reason, but 30 years of being a super mediocre skateboarder takes it's toll. It's not even so much the pain of an injury, it's mostly that everything seems to take 3 times longer to heal then it did when I was young.
Now skateboarding consists of fucking around on mellow miniramps, and doing shitty kickflips and slappies here and there. Still fun. I still keep up with all the videos and shit, and I just accept that I'm now the slow old dude with gray hair struggling with frontside rocks. It's fine.