I don't feel at liberty to analize Gordon. All I can say is, he is my oldest best friend, and you would never believe some of the things we have done. He is a man who values his privacy and doesn't do well with people who try to insinuate themselves into his circle of comfort. That's typical of Mainers; I'm the same way. In fact, there is an old Maine saying: "Be careful who you befriend, they will want something from you sooner or later." Now, we are not that bad, but you get the idea.
He's one of the finest people I know, and even after almost 50 years, I still don't know him totally.

He is at his least approachable when he is performing. His mind is on what he is doing almost to the exclusion of all else. That I understand too, having a similar mind set.

Lastly, he is not "stuck on himself", just shy.