If you are learning to play the piano, then obviously it is important to practice the piano on a regular basis, or you won’t achieve any sort of proficiency, but there are times when it is actually important NOT to practice.
The first occasion where I think it is important to give some piano practice a miss is when you are not well. If you can barely stand up or need to sleep a lot in order to recover, then don’t practice the piano. It is so important to rest when your body is telling you that your body needs rest – the piano practice can wait. Even if it is just a headache, you really are not going to get any improvement while you have a headache – wait until it passes and then you can practice.
What I have suggested so far, is really common sense but there are a few other times when it is better not to practice, that is not quite so obvious. The first of these that come to mind is frustration. When you are practicing something and no matter how many times or how many ways you go over it, it doesn’t seem to be improving. There can also be occassions when the practice is so frustrating that no matter how hard you are working, you seem to be getting worse. This is not a fun experience, but if it is something that you do experience, then it is better to stop practicing for the moment, walk away from the piano and do something completely different and then come back and try again – this usually does work and sometimes you might only need as little as a half an hour away from the piano, to be able to come back refreshed and start again.
Another time it is actually not good to practice is when you are so stressed that piano practice is not a good diversion from your stresses. If you are so stressed that you can’t switch off, then it is not really the right time to practice.
If you are pressed for time and think you can practice efficiently when you are in a rush, you are probably wrong. Being rushed or overwhelmed is not conducive to practicing the piano effectively. Besides there is no time to enjoy and really the practice becomes more of a chore than a pleasure.
These listed are just a few circumstances when it is not useful or productive to practice the piano. There could also be other reasons, but basically there are times when it is not useful to practice. As they say, timing is everything…