Invulnerable took a dive for me in my early 20's, when I developed permanent back issues. Nobody told me swinging a sledgehammer 8 hours a day for a month would hurt....

I was again reminded by the collapse of my right shoulder playing softball, the breaks in my L wrist on a trail, my R wrist off the hood of a Vette, my collarbone off a too-soft fork spring (coupled with a too-stout disc brake), and my L ankle on glare ice.

I think I got the message now.......