“If you cannot explain it simply, you do not understand it well enough.” — A. Einstein

This quote has left me in an incredible state of questioning what I do and do not understand. I do not use this to question everything; but, I do use it to know whether or not I am going to claim to understand something.

What do you understand? Can you explain it? Can you defend it? Can you question it? Can you argue for it? Can you argue against it? What do you understand?