[wallflower]

Very common. In fact, I think the hardest part of learning to play a musical instrument is the tendency to want to play at normal speed before you are ready. The idea that you can play something fast accurately when you can’t even play it slowly accurately is the classic mental and psychological conundrum.

There is a saying: “You don’t rise your level when performing. You fall to your level of practice.”

[JasonSage]

The saying is confusing and I would suggest makes the opposite claim. It’s common in sports. You practice at an uncomfortable pace to normalize it, even making mistakes, because if you can’t practice at game speed you won’t be able to compete at game speed. In that context there’s room for both, and I’d say the same for music—you need slow, deliberate practice and also reps in “performance” mode, and it’s probably too reductive to say you should “only” be doing either at any point in time.