The blog Bits or Pieces? has an interesting reference to the three stages of expertise:
It starts with someone making the realization that they want to learn about something, and don't know much about it.
They may turn into a wanna-be know-it-all, where they think they know-it-all. But for the trully intelligent, reality sets in,
and the realization is made that one knows a lot about the subject matter, but there is so much to learn. For me,
the hard part is that the more I know, the more I know I don't know. The curve seems to indicate that it only gets worse,
not better.