Richard Feynman, the late physicist who received a Nobel Prize for his work in quantum physics, made a contribution to learning by asking fellow scientists to explain concepts in simple words to test their own grasp of the concepts. He said:

Number one: Pick a Topic to Explain.

Number two: Then Explain It to a 5th Grader.

Number three: Look for Gaps in Your Explanation.

Number four: Refine Your Explanation and Teaching, then Repeat Until Clear to the Simplest Learner.

There is an excellent YouTube Video on this here.