There have been studies done on pain. Apparently, on average people who have experienced serious injuries can tolerate pain better than those who haven't.
When I was 12, my hands went through a window that I was closing it. It was stuck. I felt no pain despite the fact that my arms were bleeding due to pieces of shattered glass making deep cuts into my skin. I ended up having to get stitches on both arms. After that experience, I became very tolerant of pain. I guess it's because I know there is a limit to how painful something can be. If it's too painful, then the nerves shut off and there is absolutely no pain at all.
Giving birth is probably the most painful thing that can happen. I also gave birth to both my children without any pain medication.
I think a lot of it has to do with fear. If you don't fear pain, then it's tolerable.
Post Edited (subdued) : 1/7/2011 2:19:21 AM (GMT-7)