Do they keep forgetting?
Assume that you came to Earth last year (you were a visitor from another planet). Assume that on the first morning you spent on Earth, I showed you how to make toast. I showed you how to put the bread in the toaster and how to turn the toaster on. I taught you how to wait for the toast to pop up, and then I showed you how to spread some butter on the toast after the toast popped up. Assume that a week later, I took you downstairs and told you I was going to show you how to make toast. Once again, I instructed you to put bread in the toaster, to turn the toaster on, to wait for the toaster and then to put butter on the toast. Assume that I tried to give you the same lesson one more week later. You would likely stop me at this point and tell me that I had already told you how to make toast. You might say, "You told me twice, in fact. The steps were simple and I truly listened. There's no need for you to tell me yet again how to make toast." [More . . . ]