Atheist - Knows Everything about Everything.
They have to by definition because they claim there is no god. In order to claim the non-existance of something, you have to have looked everywhere and seen everthing.
Agnostic - Doesn't care if there is a god. They usually don't try to prove things one way or another because they just don't care. Did god use eveolution? Don't Care! says the agnostic.
Now, which are you again?