I Don't Drink, Don't Do Drugs, and I Am Not Religious
This quote by James Randi says it better than I can.
"They can easily just fuzz the edges of my rationality, fuzz the edges of my reasoning powers, and I want to be as aware as I possibly can. That means giving up a lot of fantasies that might be comforting in some ways, but I'm willing to give that up in order to live in an actually real world."