"If you can't explain what you are..." - Quote by Albert Einstein
If you can't explain what you are doing to a nine-year-old, then either you still don't understand it very well, or it's not all that worthwile in the first place.
More by Albert Einstein
“It is only to the individual that a soul is given. And the high destiny of the individual is to serve rather than to rule, or to impose himself in any other way.”
“In one's youth every person and every event appear to be unique. With age one becomes much more aware that similar events recur. Later on, one is less often delighted or surprised, but also less disappointed than in earlier years.”
“Happiness, as a pursuit, is suitable only for pigs.”
More on Clarity
More on Understanding
“Some things were beyond understanding.”
“First, what is a revolution? Sometimes I'm inclined to believe that many of our people are using this word "revolution" loosely, without taking careful consideration [of] what this word actually means, and what its historic characteristics are. When you study the historic nature of revolutions, the motive of a revolution, the objective of a revolution, and the result of a revolution, and the methods used in a revolution, you may change words. You may devise another program. You may change your goal and you may change your mind.”
“Teaching is the highest form of understanding.”