Non-smoker/drinker, formerly very physically fit person weighing in. In the five or so years surrounding 40, everything suddenly fell apart. Knees would ache after pickup games. I picked up an empty suitcase and slipped a disc. Shoulder started feeling sandy. Hands got arthritic.

It snuck up on me until one day I realized that I couldn't remember what it was to not have something hurting. I hate to say that I could easily wish it on my worst enemies, but not the average person going about their business.