It's a perspective thing. I think he missed an alternate reaction to his position. He could have been pleased with the money he was paid, honoured by the responsibility he was given, and driven to do the best he could. Instead he spent most of his time feeling hard done by. That's the kind of attitude problem that people pick up on when they consider people for a position - will this guy work his ass off for me? Oh, he thinks too much of himself? No thanks.