i usually do say what i'm thinking and i don't care if people think i'm an asshole.
the reason being; usually the people that think you're an asshole are on a much lower level, and likely can't comprehend what you're saying. if someone doesn't understand me or isn't willing to try, their opinion of me doesn't matter. alternately, the people that DO understand you or are willing to try usually DON'T think you're an asshole.
it's this dynamic that drives me to not like civilian type (read: normal, average, most etc) people.