There has been a lot of dispute over whether someone should know one thing about everything or everything about one thing. My view on that is that I would rather know everything about one thing.
For example, if someone where to know everything about one thing, such as a balloon. They would know where the rubber came from, what type of rubber it was. If the know everything then they would also know everything about the rubber trees and that goes on into soil, atmosphere, the sun, photosynthesis... etc. Also, if you were to know the absolute everything about one thing, you should know the things that scientists haven't even discovered yet, so they would consider you a genius, and since one thing stretches out to all the other things, you would end up know everything about a few things rather then just one.
When you know one thing about everything, you simply don't know as much as the other option.