I'll be 62. Retired US Army infantry. 30's you lose a step. 40's lose another step. Aches and pains set in from the 20's and 30's. 50's is when you hit the wall. 60's you are so used to aches and pains that you don't care or have a filter. You grin and bear it and laugh at young people whine.
I wouldn't change a thing.