This was inspired by Dawn Casey’s article on learning programming.
Personally, I like to think about knowledge on any particular topic as an iceberg. There are three types of knowledge, and learning is the process of moving around the iceberg of knowledge:
What you know you know – this is the part of the iceberg you can see from where you’re standing at this very moment.
What you know you don’t know – this is the other side of the iceberg, that you can’t see from where you’re standing but is obviously the other side of the iceberg, just over that peak in front of you. It may be slightly larger than you expect, but in you’ve got a good idea of the shape of it from looking from where you are. You may climb to a higher point on the iceberg to see more of it.
What you don’t know that you don’t know – this is the majority of the iceberg, underneath your feet. It’s large, and epic. It’s always bigger than you can reasonably imagine. It takes specialized equipment and knowledge to be able cover every inch of it on the outside, and careful dissection to get to the center.