Head shaving *Spoilers Kinda*
I'm bald on top, so I shave my head. The shaver he was using in the movie had a spacer/head-skin-distance-protector on it. As much as I think he's a badass as an actor - he woulda had more hair on the spots he shaved.
Just sayin as a prof head shaver...
"I do not like mixing up moralities and mathematics."
Churchill