Yeah, I wasn't contradicting anybody here, unless you're saying pro sports don't have a history of 'shaking' off concussion. In contact sports players head injuries are treated in a way more cavalier attitude than MMA (though its slowly changing), mostly because people seem to take human 'intent' much more seriously.
Like people worrying about terrorism as they drive their car using their iphone. People see fighting and think 'this is much more dangerous' than Football.
And yeah, head injuries and concussions should be taken very seriously.