An old one, but I thought it would be worth posting here too.
A dialog between a doctor and his patient
D: How are we feeling today, my dear boy?
P: Ok (if I overlook being psychiatrys toy...)
D: I'm here only to help you (You're as mad as they come.)
P: Doc, I'm in thouch with reality (just not your particular one)!
D: Come now, reality is a serious matter...
P: How come you're so sure, yours is so better?
D: I can see it, smell it, feel it by thouch...
P: So can I, you should know that doesn't really say much.
D: My path is the one, where the science has walked.
P: Yeah, I hear a few years ago the lobbotomy rocked!
D: That was a little misunderstanding, a small, insignificant stain!
P: You mean like the one between the Bush and Hussain?
D: It doesn't change fact, that you're living a lie!
P: Come on, what's the difference between you and I?
D: The difference is in the Truth I did obtain.
P: Not the truth, doc, just your own licence to be insane...