Comments like the latest in the Double Helix Water thread always make me think of this:
“Alice laughed: “There’s no use trying,” she said; “one can’t believe impossible things.”
“I daresay you haven’t had much practice,” said the Queen. “When I was younger, I always did it for half an hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.”
Alice in Wonderland.
But then the author was a mathematician!