Maybe being clever is really stupid, and being stupid is really clever.

Is it ego or arrogance? Is it the need to present oneself as an intellectual being that results in really stupid decisions? I guess so.

Intelligence, knowledge of what's coming next. Really there's no need to abuse it to spoil the fun of others and make oneself unlikeable. Everyone just wants to have fun. In such cases, feigning ignorance might be much better off. You don't suffer much, the people around you are happy.

Why then, do we trample over others just to prove ourselves?

It is really in our blood to be compeitive people who always want to prove our existence, our worth, our prowess?

Of course, things pretty much depend on the people you are with. In a group of self-praised, honoured intellects, fools will just get ostracized. Then among the fun-loving people whom does not really care how much another's IQ is, just let go of yourself and be the idiot we always are in our most relaxed and primitive states.