People who just have a surface knowledge or just learned some stuff by watching national geographic or some pop science thing seem the most willing to impart knowledge.
I think we can learn a lot from beginner understanding, especially as it pertains to ourselves delving into new subjects and getting our baby legs with new technologies and approaches to technology.
There is no point in gaining a whole bunch of knowledge if you are not going to pass it on somehow. You are not going to use it as you decompose. I think that the cleverest people I have met were also really good at explaining things in terms that almost anyone could understand.
In fact, I think that not being able to explain something to a 'layman' is actually indicative of having a superficial understanding of a topic. Even if there is a large amount of superficial (memorized) knowledge, there isn't necessarily any insight.
The best way to learn and remember and understand anything, for me, is to try to explain it to someone else. It is the easiest way to really think about a topic.