Well, my dad has an insane tolerance for pain.(He hammered his thumb with a carpenter hammer and didn't even swear). Mine's not as high as his, but I kept weighlifting right after I first subluxed my shoulder and finished my workout.
I think pain tolerance is mostly in the mind. Guys never want to look weak in front of their dads, sons or other guys. It becomes so habitforming, that the mentality is there at all times. I like the old saying "Walk it off".