Often we are in a hurry to learn a piece because a deadline is looming. So we don’t take the time to play every note perfectly and slowly in order to burn the correct patterns into our brains. If we practice mistakes, lo and behold, we learn mistakes. The biggest mistake is to practice tensely! However, with all the most careful preparation in the world, brain cramps can still occur, but they are less frequent. The trick is to know how to recover, without broadcasting to the audience that you are mortified and forever disgraced. As long as our correct notes vastly outnumber our errors, a mistake is not the end of the world.