With all these things, I would argue, that you through a kind of 3rd order polynomial experience of time vs. your confidence in your own knowledge. At first you know nothing, and you're aware you know nothing. After some short amount of time you've learnt a huge amount, relative to what you did know, so you feel like you have a good grasp on the topic. But, over more time, you begin to realize how much you actually don't know (which may reflect everyone, or just reflect yourself, the latter meaning you can learn from others, the former meaning you better get your thinking cap on). Hopefully then over EVEN more time you begin to slowly increase your knowledge base, but this time from a more informed perspective.
The point is, I guess, that it's hard to assess your own knowledge of a topic at this very moment in time unless you've spent a decent amount of time getting your head around it's true complexities (where both, "a decent amount of time" and the true complexity of the topic will vary HUGELY from case to case).