I act childish & stupid, even though I'm actually pretty smart- although after I behave that way & say weird things, & people reject me constantly because of it, it convinces me that I am retarded. I've always attributed this behavior to my reclusiveness & anxiety (how can you develop social skills if you're never around people?). Is it a common trait of Bipolar Disorder ( I may have type 2) to behave this way? I thought I was the only one, too, until I read this thread.