Natalie Angier retells a great story in today's New York Times, in an article about men and pain:

Heard the one about the husband who agrees to be hooked up to a machine that transfers the pain of childbirth from the laboring mother to the father? The doctor sets the dial at 10 percent pain level, and the man feels nothing. Thirty percent, again nothing. Fifty percent, ha! not a tickle. Finally, the doctor cranks the dial to full-bore, pass-a-pachyderm-through-a-keyhole stage, and still the fellow shrugs smugly and says: "Feh! I've had worse pain from clipping my toenails."

Returning home from the hospital, the couple find the mailman dead on their doorstep.