OMG, I forgot about his drinking and singing antics, Beer Barrel Pooka, Mary Had A Little Pooka, Pooka Me & A Dog Named Blue. Goes on forever.
Then the bragging about creating the light bulb and the one that still burning in that fire station was his and not Tesla's or Edison's.
Oh, and never ever let him be the designated driver because he says designated drivers drink for free and when you get pulled over by a cop guess who's nowhere to be found?