Sherman has said publicly that he was very reserved growing up. There is substantial reason to believe, imo, that he developed that persona for competition.
I mean, if you really watch the famous "out burst," you don't see a guy who's carried away--heck, he even stops to let Andrews ask a follow up question which he listens to. He also greets Andrews warmly and hugs her before the interview.
The thing was an act and America bought it. There's a gif of the hug
here along with many other reasons explaining how awesome he is. Check out 19 on his charity work and
this on his anti-bullying work.
I know this is a bit off topic for the thread, but I think we can afford to be magnanimous in victory--much like Sherman himself was.