There was an elderly couple who were getting more forgetful, so they decided to go to the doctor.
The doctor told them that they should simply start writing things down, so that they don't forget.
They go home and the old lady asks her husband to get her a bowl of ice cream. "You might want to write it down," she said. The husband said, "No, I can remember that you want a bowl of ice cream." She then told her husband she wanted a bowl of ice cream with whipped cream. "Write it down," she told him, and again he said, "No, no, I can remember: you want a bowl of ice cream with whipped cream." So he goes out and spends some time in the kitchen.
He then returns, and hands her a plate of bacon and egg.
The old wife stares at the plate for a moment, then asks, "Where's the toast?"