Similar story here. I was strongest in my 20s, while I was in the military. Did a lot of physical stuff outside of organized PT. Ran and rode a lot, especially in Okinawa. When I got out, my goal was to just "maintain", but life got in the way. Someone challenged me to a 5k about five years ago. I didn't do nearly as well as I expected. So much for maintaining. But I pushed to get back in shape. Then someone challenged me to do a triathlon. I signed up for April of 2020, then the WuFlu hit and all events shut down. I did my first triathlon last October, at age 51. This one was my fifth in 10 months, also fifth ever. Didn't start triathlons until I was in my 50s. Now I'm regretting not starting younger. I really wish I had at least attempted an Ironman back when I actually had a reasonable shot at finishing one.