I thought about this when I first saw the thread a few days ago, but I didn't have an answer. I saw it again yesterday, and thought about it more (actually, for a few hours). And now I've been thinking about it most of today. I still don't have a good answer. I know there are things people have said to me regarding who I am or some aspect of who I am which have suprised me because I don't think they are accurate, but that doesn't necessarily make them wrong. More importantly, I don't really know what conception most people have of me, and I don't really have a conception of self to compare it to. The one I had (as much as anyone does), I lost. And when I did, I increasingly realized that so many of the people I spent time with, made no impression on me. For example, I spent months tutoring a student one-on-one every week, but I only know this because she told me when we happened to be talking maybe a year (give or take a few months) later. I had no recollection of her at all. It turns out this is the norm for me.
In order to know what misconceptions people have about me, I'd have to know what people who spend time with me think. But apparently not only do I not remember what they seemed to have thought of me or explicitly told me, I don't remember them.
I know this doesn't answer the question. But the easiest way for me to stop obsessing about the question was simply to respond with something. And even though it isn't remotely comprehensive, the above already resembles too greatly a diary page in some movie intended for teenagers in which a young DiCaprio type narrates as he is writing.
Lisa: It may be bleak, but this music is really getting to the crowd.
Bart: Eh, making teenagers depressed is like shooting fish in a barrel.
-- "Homerpalooza"