It's mostly because I'm so out of it most of the time. I'm usually in my own world, so people, especially my family, have gotten used to the idea that I don't really have a grasp of what's going on at the moment, it takes time for me to get in touch with reality. Mainly, when it relates to those daily life things like chores, I get patronized a lot. "Here, I'll do it" is something I hear all the time, because they just assume I'm not going to be able to figure out what to do or whatever.
With my friends, I guess it happens with those callous people who assume that just because I'm not loud or going out of my way to be assertive or hanging a big neon "I'M THE BOSS OF ME" sign on my forehead, that means I'm a doormat. I almost always end up proving them wrong, so it doesn't bother me much.