I'm guessing you're not fat because, let me tell you, people are bothered by fat peoplen all the time. I am overweight, and no, I don't appear thin when I'm walking around. But you say that like walking around fat isn't also sometimes embarassing for fat people. And it's entirely different for people to see you struggle to fit into something that most other people have no problem with. If I'm walking around in the world I'm not it's not like I have to squeeze myself into it. Do you seriously not understand that fat people are judged and ridiculed all the time? Yes, those people are jerks, but that doesn't mean it's easy to ignore and not be bothered by it.
I'm jumping off topic just a bit to say this: I've been fat since I was eight. I've lost and gained and lost and gained and lost and gained, so I have some experience with the subject. I'm someone who didn't fit FOP and had to be escorted out to the waiting room.
And I can tell you, I honestly believe other people don't care. Unless you're actively getting in their space -- crowding into an airplane seat, os scrunching them in a theater or something -- they don't care at all. They rarely even notice. And even in those situations, they forget about it soon after. I think the embarrassment comes mostly from us, that we assign other people a level of judgement and malice they don't really feel. I'm 50, and the last time someone actually SAID anything cruel to me about my size was junior high. They may have felt it, or they simply may not have cared. The shame and emotion I felt was strictly from me.
I'm not suggesting that your emotions aren't real, because I've felt them and still do. But I think we spend too much time worrying that other people are pointing fingers at us. Because, as much as we might feel embarrassed about our size, I honestly don't think the rest of the world cares at all.