Reaction to League of Denial

League of Denial was a documentary about how concussions are starting to become a big issue in the NFL.  It showed the side effects on the players brain after years of playing football.  They have linked brain damage later in players lives to the concussion they have received playing football.  As a golfer this is something that I do not have to worry about as concussions in golf are pretty much impossible.  I have never heard a story where a golf has received a concussion or second impact syndrome.  This is something that does not cause a concern in golf and is never going to be a problem.