Funny observation you made about practicing slowly. Indeed, once you increase the speed, you effectively need to start from scratch and it feels like you relear

Funny observation you made about practicing slowly. Indeed, once you increase the speed, you effectively need to start from scratch and it feels like you relearn what you are doing. I'm a mediocre hobbyist piano player, but it resonated with me. Hoever, one day I exercise and even after some serious effort I can't seem to play the bars without error consistently. But I can the next day after the first try.