Why do I get "brain freeze" when I eat ice cream?

Why do I get "brain freeze" when I eat ice cream?

Professor Gizmo (Amazing Science Presentations) gives expert video advice on: What is my body made of?; Why do we get "goose bumps"?; How do I catch colds? and more...

Well, when you get a brain freeze and you're eating ice cream, boy doesn't that hurt? What's actually happening is you're freezing the lower part of the brain behind your throat, and that seems like it's a very painful sensation.