Learning in University

My mother read me this Chinese joke which I thought was actually quite apt:

In your first year of university, you don’t know that you don’t know anything.
In your second year, you know that you don’t know.
In your third year, you don’t know that you know.
In your fourth year, you know that you know.

Well, so far I’m on track with that, but I really question getting to the third stage.