Authors:

There are places on a man's head that are as hard as a rock. Your head's actually stronger than your body. And you don't have too many instruments up there workin'.

"Joe Frazier: What I've Learned" by Cal Fussman, www.esquire.com. November 7, 2011.
There are places on a man's head that are as hard as a rock. Your head's actually stronger than your body. And you don't have too many instruments up there workin'.