Carl Sagan, The Amazing Randi, Penn Jillette, and…

fellow skeptic Wally.

I became suspicious when I cried over spilt milk and the cashier took it off my bill.

Brilliant.

For the really curious:

skeptic
(A skeptic is someone who critically evaluates claims, usually of the paranormal variety, though it can be applied to common truisms or, say, anything Johnny Chimpo says.)