Cure4all, you are not alone. I am grateful for the few people who have enough humility to ask or theorize only about experiences that they have actually never been through, rather than play act as though they have. Unfortunately, most people have learned that it is never okay to openly admit ignorance or insecurity, so they take up defense mechanisms by playing expert, acting arrogant, assuming other people's boundaries to be negotiable, or speaking/acting offensively.
Sometimes, I just pass it off...and I have seen people have an odd, odd way, sometimes, of trying to bond over things. I completely miss the point sometimes. I think that what you are describing may in part be human nature in its unfettered glory...sometimes. Sometimes, I suspect that people feel oddly alone with a person w/T1 when they know just enough to realize how...what's the word...how all encompassing it actually is, how sick it can make anyone with it feel...as though they sense that there is this element that they'd like to and at the same time not like to mess with themselves.
If they are friends, real friends, they will have mixed up feelings about your existence with T1...when I was your age, no one really liked to bring certain feelings out in the open, which was depressing, really. It won't be an attitude as much as something they can't really name; I tend to think, from personal experience, that a rigid attitude toward others is generally only a shield, and a flimsy one at that...and the best friend of all will try, somehow, to level the playing field, not only between you and him or her, but T1 as well.
You are refining the art of being a friend as you tolerate and set boundaries with those who, by the way, may feel helpless, too. Your post made me think about how I feel when I can help someone else; it feels like relief, somehow...from what, I'm not sure...but it is freeing to feel like I am contributing and helping out.
Don't assume that anyone is out for the worst, even though it may be right there for anyone to see...this is also from personal experience. There are good people in the world who may act poorly sometimes. Just be yourself. You're helping your friends, even the misguided ones, if you can allow them to learn their own lessons.