Not feeling pain can have some really disabiliting effect on one's life. A rather famous player in the Counter-Strike community suffers from a rare genetic disease that make him feel much less pain than normal. He started to scratch his nose out of habit when he was a kid, and eventually it came off over the course of years of scratching. His name is lo0p__ : https://www.twitch.tv/lo0p__

Edit: You can see him explain the effects of not feeling pain in this video - https://www.youtube.com/watch?v=XalQkahQbpE