How could I forget? *This* is what Rob, and Jill, and I were talking about yesterday. Jill found this Post-It in one of her library books, and I was imitating the dad upset about the Sharpie accident:
It couldn't have been in Freakonomics, right? The Post-It went on to say (on the back and upon a subsequent, attached Post-It), "Did you know Sharpie is permanent? It doesn't come off no matter how much you lick your finger and rub!"