Yeah mate its a fine balancing act ego is required to acheive and progress and remove the oposition when the times ripe or as a turn around post but theres a big but if you let emotion in while training it rears it head in the same situations cause we are are creatures of subconcious habits.
Some pros get caught up in the wrong side of ego and are easily taken to a ground they then f@ck up in.
We've all seen the effects prior to the fights on words and in the ring on over agression.
Funny timing but the fit Vargas of old comes to mind as someone who could be taken off his game through it i and out of ring.