Jekyll & Hyde-ness

I dont have a multiple personality disorder but sometimes I think some family members posesses this trait.

I have a uncle who reminds me of the theatrics of the mel gibson tapes. When I have a conversation with him I have to remain calm and if its over the phone and he's acting bonkers then I disconnect the call. But the weired thing about him is that less than 30-minutes later we'll have a conversation and he'll act like a meltdown never occured!!