This took place when I was 50-ish.

I was just out of the pool, had been trying to keep up with the HS swim team for their entire workout (using a faster/more punishing stroke than my usual glide). I laid myself on a locker room bench, feeling all of my years. I announced to the room “Oh, god, I wish I was thirty again!” One of the guys I swam with regularly responded: “Thirty? Hell, I wish I was eighty again!”

BTW: Am I the only person who feels the year before an ending-in-zero year is more traumatic than the actual year?