Reddit reviews The World's Strongest Librarian: A Book Lover's Adventures

I'm also thinking Tourettes. The smacking in the head and weird vocalizations is classic Tourettes. My brother is on the autistic spectrum and also has Tourettes and other than the calculations this is all really familiar to me, exact same description, been weird since a kid, mumbled/talked to himself, instead of smacking himself in the head, he'd enter another world when he thought no one was around and he'd walk around in circles mumbling to himself with facial ticks and he'd every third step or so stomp the ground. But there are tons of those with Tourettes that smack themselves in the head.

Also my brother - good father, successful, has friends, can be socially awkward but is kind and engaging.

Since this has been going on through his life an not manifesting later in life (common for schizophrenia to manifest in the 20's), I'm thinking autistic spectrum with tourettes. Your father and my brother could be twins.

I've done a lot of reading on tourettes and probably the best and most accessible book, even though it's a memoir is "Worlds strongest librarian", it really delves into tourettes and explains it well. The author talks about punching himself in the head, how it builds up and he knows it's coming but he can't control it, this may give you insight into this.

http://www.amazon.com/The-Worlds-Strongest-Librarian-Adventures/dp/159240877X