The point of saying that is to inspire people to just start trying now. People cannot choose to become younger.

Technically you're probably right, but I think this feeling affects people who trained to be competitive at something when they were very young, then stopped and stagnated, and then tried to pick it back up after their divorce or letting themselves get a beer gut or something. The feeling of not being the same as they were in high school or whatever.

I was reasonably athletic, but never tried to "train" or got even close to what peak might have meant, and then continued skateboarding and doing other athletic things throughout my twenties, always being in pretty good shape. Now in my thirties, I'm in my best shape and continuing, it doesn't really matter what my peak hypothetically could have been or where I was at earlier, past is the past, let the good memories stick around, let the bad ones disappear, be present and keep pushing into the future.

Maybe I consider it a blessing that I never tried that hard in my early years, because now I'm not concerned about any ceiling. I let the enjoyment and ambition guide me, not the numbers, who cares.

I've had a concept 2 rowing machine for almost 20 years, so I (automatically) have a detailed record of every workout for two decades. N=1, but for me at least, I have clear evidence that the same level of effort does not produce the same result as you get older. onsistent effort does produce results at any age (that I've reached at least).

Yeah, I only started taking fitness seriously at 39. I'm now 41, and I'm glad I did, I might be in the best shape of my life.