To echo a previous poster who says people are a pain, wasn't it Satre who said "Hell is other people"?
Close, it's from a play by Jean-Paul Sartre. By the way, "L'enfer, c'est les autres" is said by a character, and does not exactly mean that other people create Hell, or even that interacting with others is Hell.
Isn't a bit more complex than that, it has something to do with our self-knowledge being a product of the way we are reflected in the the eyes of others.
I'm not the one to try to explain it, I've always seen existentialism, phenomenology, and even philosophy as a whole as a victory of style over substance. Give me problems that need to be solved, and ways of measuring my progress in doing so. If I care about how someone sees me, I'll do something about it. As for how I see myself, it's mostly about what I can achieve.
I may have married a professor of Psychology, but I'll always be an Engineer at heart