Ganton Syndrome 

When someone has a unrealistic perception of their own competence and / or importance within a team or organization. Degrees of Ganton Syndrome are often inversely proportionate to the actual capability of those who suffer from it.

Tom: Why the would Gary think he's capable of running the company when he's at best, a shitty secretary?
Jim: He must have a bad case of Ganton Syndrome.

Ganton Syndrome by Gantoning July 24, 2016