Of course it is possibile. I did it alot when I was younger. You just need to watchout not to bite through your skin... Also, biting the skin off, on your fingertips, on sides of fingernails...
pulling a hair out of my ass crack.. I should clarify- not ass hair, like a long hair from my head that somehow made it down there..
As for my own strange thing that feels good, I'm gonna say... winning a plushie from a claw machine! I won this puppy looking cow today.. i.e. obtaining something that seems unobtainable, accomplishing something others won't even dare try..
When you are in public and you keep blowing your nose because there is a booger stuck there and it won't come out. When you finally are in private and can just pick the darn thing out and be at peace. How they get stuck I have no clue.
I like sticking things in my ears. I also like sticking thing pointy things in my nose and then sneeze. I'll do this multiple times a day. Sneezing is awesome.
I love having my head massaged. Almost every night my fiance does it for me and I swear I fall asleep with him doing it. I don't know why it feels so good.