Let me see...

[He ticks them off one by one on his fingers, hoping that smile on the kid's face is a friendly one.]

Talking to yourself, becoming paranoid, hallucinating people 'n things that aren't really there, losing a grip on reality, and finally retreating into your own little world. Those are the big 'uns.

[He pauses and considers what he's just said.]

Shit. Maybe I've gone mad and never realized it.