When I was younger, even in my 40's, I worked on cars and bikes all the time, sometimes all day, sometimes all weekend, sometimes all year. It never bothered me.
Today I replaced the stator on the alternator on my cycle, a job that would take a Harley dealer about four hours to do. Between the heat, two trips to the auto parts store, and my dilapidated body, it took me about eight.
I ache all over. My back hurts from being bent over, my legs hurt from squatting, and my neck hurts from twisting it around to look at parts on the bottom of the cycle.
I hate getting old.