Repetition versus iteration
Repetition is performing an action over and over again.
Iteration is the deliberate attempt to perform an action in a manner that is superior to the last time you performed it: think better code than what you’ve written before, playing a song more smoothly than the last time you played it, etc.
If you cannot clearly tell whether you’re repeating or iterating, it’s because you don’t have a clear feedback mechanism that informs you if you’re improving or not.
The additional danger of repetition is that you can end up practicing the wrong way to do something — an inefficient way to code, a poor playing technique that will hold you back from playing an instrument proficiently.
It’s important to recognize any instance of repetition in disciplines that matter to you, and to convert them into iteration.