Running Blind 1-53

I have just began Running Blind by Lee Child. This is my first Jack Reacher novel, which from what I get is a book series based upon a character called Jack Reacher, who is an ex military police investigator, who got laid off when his unit got closed down, and is now for some reason trying to be untraceable. I have not yet got to a good part yet, so it's a struggle to keep reading. My quote is from the begining of the book when he is getting mugged by 2 guys.

He hit the right-hand guy in the side of the head with his elbow. Lots of good biological reasons for doing that. Generally speaking the human skull is harder than the human hand. A hand-to-skull impact, the hand gets damaged first. The
elbow is better. And the side of the side of the head is better than the front or the back. The human brain can withstand front-to-back displacement maybe ten times better than side-to-side displacement. some kind of complicated evolutionary reason. So it was the elbow, and the side of the head. (12-13)

This is the most interesting paragraph of the book so far to me for many different reasons. Fist of all, I didn't know this character at all and then it has this paragraph. I got that he is probably very skilled an fighting and that he always thinks thoroughly about all his actions before he does them. Now I have a much better understanding of this guy and what the author is trying to say, don't mess with Jack Reacher.

Child, Lee. Running Blind. New York: The Berkly Publishing Group, 2000.