I recall a converation I had not too long ago, I friend of mine has asked me whay I don't teach Martial arts anymore and there are a few reasons, but he said something relevant to this thread:
Lots of guys teach, they don't know jack but they think they do, and many don't teach and they know so much, why?
I replied that, for some, they realize that, no matter how good you are, there is always someone better and always more to learn.
This has been my experience with the vast majority of elite fighters and MA that I know.
An Overt and outgoing arrogance is usually the sign of some oen trying to compensate for a preceived lacking they know they have.