The beauty and the pain

Wonder: why people feel the pain so differently? Is there a link between the body and the mind?! Are those who believe are stronger, stronger then the others?!

I had to see the dentist for so many times and I had so many problems with my teeth, but every time I went to see the doctor and the procedure implied an injection to calm the pain, I was told that I have a better reception to pain. Why is that? It is known that when you're afraid of the procedure you tend to feel the pain even more badly than actually it feels. And I Believe it's true, even if last time I saw my dentist he told me that I'm going to feel more pain with the paladin injection, it wasn't like that at all: the pain was as usual, just a pinch and that was all! ;-)