Even Bach Played Scales.

I don't have any proof of this. Typing "Bach Playing Scales" gives you some discussion about how Bach's tuning isn't the same as our modern piano, along with some discussions about Bach's Inventions (practice pieces he devised) using scales. But there's little record of Bach actually playing scales. Yet we can be assured Bach played scales, just like I can be assured Neil Peart plays the rudiments, and other great musicians practice fundamentals in order to stay sharp and perform at their peak. Yet they don't have to make a big deal about how many scales or rudiments they play; they just do them. It's all part of their craft, much the same way carpenters sharpen their tools.

It's all part about making ourselves ready for the work at hand.

No matter what you do, whether it's programming, performing, or even presenting, you'll need to practice in order to maintain your edge. None of these happen in a vacuum, and constant vigilance is necessary in order to keep that edge. And it needs to be consistent. Few people can cram years of practice into the span of a few hours.

It's interesting Bach's practice pieces are called "Inventions". Perhaps practice is the mother of invention after all.