For me, the need to be an expert stems from my need to know every little bit of information. "Ego" only comes into play when somebody "challenges" me that they know more than I do about one of my strongest special interests. But ego has nothing to do with why I need to become an expert on a specific special interest in the first place. That stems from an obsessive-compulsive need to have all of my questions answered and not have any ambiguity. I desire this in all aspects of life, but when it comes to my special interest, I can actually DO it. I have spent many an hour mulling over very insignificant details pertaining to my most intense special interests, trying to find the answer to an unknown question most people don't even think twice about considering.
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Helinger: Now, what do you see, John?
Nash: Recognition...
Helinger: Well, try seeing accomplishment!
Nash: Is there a difference?