Often lost in a world of his own. If he doesn't respond to you, leave him be - he'll find his way back to this world in a while.
Has an extreme sense of humor. Tell him any joke - any joke at all, and you can be sure he'll be the first to burst out laughing on the floor... *giggle*
Loves cats. He'll try to approach and play with any cat he finds in the streets. But strangely all the cats avoid him like the plague... *sob*
Probably a paranoid. Thinks he's always hearing someone calling his name or his cellphone ringing when nothing of the sort ever happened. The "sixth" sense? Maybe... ("I hear dead people" maybe?)