Labor pains.
Experienced at most once every nine months and can be anticipated, and nulled with an epidural anesthetic since a hospital is the typical destination when it occurs.
A hit to the balls.
Constantly exposed to the threat, can occur without any warning, and is rarely warranting a hospital visit. And to top it off, it seems that many women see this agonizing pain as comedic.
And who's complaining?

Now if you're one of those women unfortunate enough to have gut-wracking menstrual cramps, then I don't take issue... I've seen what it does to my sister.