Seeing as I have a rather insatiable curiosity with inane trivia, this quote on Story People was just perfect for me.

The top of his head was open up to the sky & when he walked down the street he'd end up with strange things in there like the number of dogs in China, or the time it takes to cook a pig. It's not really useful, he said, but I'd miss this stuff if it ever closed up.

I keep trying to see the top of my head to see if it looks the same... guess I'll have to get a mirror.