This is why you wear a helmet

Giro couldn't have asked for better PR:

A white paneled delivery truck ran over a UW-Madison graduate student's head on Division Street Friday afternoon and, except for a concussion, he wasn't hurt.
...
"I didn't see it coming, but I sure felt it roll over my head. It feels really strange to have a truck run over your head."

I tend to agree with commenters on the linked page that a bike helmet wouldn't really do that much to protect a head from a direct rollover, and that this guy may have had it strapped on too loose, allowing his head to be squeezed out (maybe that's what really saved him), but at least it kept his skull from cracking on the pavement. And damn! that's a gnarly sight.