Much of what I know about learning is informed by my experiences learning to play music back in my youth.
When learning an instrument, once you get past the very rudiments of technique, you'll be given scales and arpeggios to learn. Scales and arpeggios are pretty boring to practice, but any instructor worth her salt will tell you that they're the foundation of musical technique. It's a practice that never goes away. Even concertizing musicians work on scales and arpeggios.
Beginning musicians work on simple pieces of music, too, to begin to put technique into practice. If you played a classical instrument as a child, or if you've ever been to a little kid's recital, you know the kind of pieces I mean, the ones written by music educators and collected into books with names like "Delightful Easy Piano Pieces Vol. 14." They're tolerably inoffensive and completely forgettable. These pieces give students with limited technique the opportunity to do something that is (more or less) making music. Learning these pieces is useful, in that it's a bridge to higher-level pieces, but they're not something anyone really wants to listen to--again, if you've been to a kids' recital, you know exactly what I mean. These pieces are learned because they're useful, and then set aside.
Though the foundation can be strengthened, it never stops being the foundation. What is built atop that foundation, though, changes as the underlying skill increases.