Why do we view the boundaries people create for themselves as challenges? Why do...

Why do we view the boundaries people create for themselves as challenges? Why do we see someone setting a limit and then try to push? Once, I was at a restaurant with a large group of people and the waitress kept touching me. It was really fucking annoying because I don't want to be touched like that unless we are in a sexual relationship. Every time she passed by, she would rub my shoulders or run her hand down my arm and I kept getting more and more irritated but I said nothing. I never do. Do my boundaries exist if I don't voice them? Can people not see my body, the mass of it, as one very big boundary? Do they not know how much effort went into this?
Because I am not a touchy-feely person, I always feel this light shock, this surprise, really, when my skin comes into contact with another person's skin. Sometimes that shock is pleasant, like Oh, here is my body in the world. Sometimes, it is not. I never know which it will be.