Thanks for sharing!
I can really relate to number 2. There have been times when I have felt a bit woolly on a subject, and then I have explained it to somebody at an earlier stage than me. Usually I surprise myself with how much I actually know and then like you say; sharpen my own understanding.
I would love to chat physics with you; I have so many crazy ideas (not backed up by maths) that I would love to talk with you about.
For instance I'm interested to know if we could trigger a second iron catastrophe on Mars and thus create another magnetosphere. I would want to do this by burrowing deep into the planet (with an, as-yet-undiscovered material) and pouring in molten iron.
I know there are gravity issues, but surely we could do this one day?
Anyway, I digress, thanks for your comments! :-)