When your pain tolerance increases after you expose yourself to pain many times, do you actually "get used to"?

A sensitivity to pain is many times a lack of vitamin B-1. Your tolerance to pain is a lot to do with if you are scared because of it. When you know what causes your pain, and it is not something that will rise the fear in you that you will die from it, it is tolerated easier. It can be ignored to a large degree, it depends on the person and their attitude toward pain, for many pain is "bad" for others it just is, and they deal with the isness of life with no preferences. But there is something, I do not know what, like when I was a cook the cook said look I can put my hand on the grill, he did so and did not get burned, after three months I could do the same, I do not know why.