Mr. Sheldon is an old man who is a nonce, he's obsessed with one particular student in his maths class. Therefore, if you may know any Mr. Sheldon, i advise you to stay away from him at all costs.

A cultural and aesthetic mind-state that prioritizes making money, even as an “underground” or “radical” creator. The work isn’t made for money, but it’s the money that matters the most.