I think we all do that though. It's almost like a constant tug of war. People are kind and friendly and as humans we want to be close to people. . . but then there's always that fear that they'll realize you aren't who you say you are, or you don't fit there, or you're just faking it. . . so the options are that either they find out who you "really" are and they run off, or you run off to avoid being hurt. . . so you run off. . .
It takes some really good friends to put up with that tug-of-war game. . .
I don't mean to be a contrarian, but that's not uncommon among NTs, either. Maybe it's not as common or omnipresent for most, but I kind think feelings of isolation & loneliness are part of the universal human condition.