I've had similar experiences teaching juggling. I think this applies to many, many physical skills. When you learn to juggle, you try your hardest not to drop

I've had similar experiences teaching juggling. I think this applies to many, many physical skills. When you learn to juggle, you try your hardest not to drop the balls, when actually the most important thing is good fundamental form. Convergence on success looks rather sudden because you eventually stop dropping the balls as a result of your form improving, not because you were trying your hardest to keep the balls in the air. In that case, it's getting the throws right. But that means practicing the right throw in the first place. Perfecting the throw, then perfecting the part where you catch it, that'll come with practice, but first you need to stop handing the ball to your other hand. I'm trying to learn to juggle five balls, and the same thing applies. I can get to 10 catches/throws, but to get to 100 I don't just keep trying to juggle five balls, I try to juggle three in a five ball pattern (juggle two invisible balls) and perfect each throw, or juggle four balls in a five ball pattern and focus on consistency, because you aren't consciously improving if all you're trying to do is keep the mess of throws in the air just a little longer. That applies to singing, playing instruments, golfing, competitive gaming... everything. Sometimes you're not optimizing the right thing in order to get big picture results.