I definitely know what you're talking about! This means you're developing strong muscle memory, which is good -- but having too much dependence on muscle memory

I definitely know what you're talking about! This means you're developing strong muscle memory, which is good -- but having too much dependence on muscle memory is something to watch out for. It's dangerous because: - Muscle memory is extremely transient; it starts to fade a bit after just a day or two of not practicing one specific piece, and drops off extremely quickly the longer you go. - Your sense of timing in muscle memory is based on how long it takes for you to physically move your fingers, rather than on the rhythm of the piece. This means that as your muscle memory gets better and better, you unconsciously and inconsistently speed up, causing you to actually become worse at maintaining a steady tempo. - Muscle memory immortalizes bad technique/"shortcuts" that you took early on in learning the piece. This can cause sloppy playing; inconsistent ability to nail tricky sections; an inability to push the piece beyond a certain tempo; or even repetitive strain injury. - As you observed, your muscle memory can't get you back on track if you get disrupted. - Muscle memory doesn't work when you're playing with other people, because you need to be able to consciously adapt your playing to your bandmates. - You can't improvise/transpose/adapt your playing on-the-fly when relying solely on muscle memory. - Muscle memory will randomly fail you at the most inopportune times, especially when you're nervous. It's no fun to suddenly forget all your music whenever you try to play in front of people! My piano teacher taught me a variety of practice techniques designed to disrupt muscle memory; to force me to be able to play a piece because I know it in my mind and not just in my fingers. For example: - Metronome! Lots and lots of metronome practice. Putting it on the metronome trains you to play to the pulse of the piece, and playing at a variety of speeds disrupts muscle memory because of how timing-dependent muscle memory is. My teacher recommended starting each practice session by playing each piece half-speed on the metronome, and repeating a few times at increasing speeds until reaching my desired tempo. - Practicing in "rhythms": play a section (with just one hand), pausing briefly after every other note. Then play it again, but pause after the other notes this time. For me, this does wonders for tricky scale-like runs, because those little pauses force me to consider each transition between notes. - "Backwards practice": play the last measure of a section, then play the two last measures, then the three last measures, etc. This is remarkably effective for me, especially in learning how to resume playing the piece anywhere rather than just at specific spots (which is really important for being able to smoothly recover from mistakes). All of these practice techniques are infuriating, because suddenly really easy stuff you can play in your sleep is hard! But the goal is to reach a point where you have comfortable muscle memory, and are able to play without thinking too hard about it -- but you also have the "head knowledge" to keep you on track, and to fall back on when your muscle memory suddenly fails you.