It's not the progress that's important in one's practice; it's the many plateaus that you work through.
Try reading the interview with George Leonard sensei
on this site. He says it better than I can. One section reads:
George Leonard sensei wrote:
I think one of the things that characterizes almost all of [the people who are very advanced in their field] is that they're not only willing to stay on a plateau in between spurts upwards for a long time and are not only willing to practice, but also love to practice. And, if I can make a radical statement, they can love the plateau.
We all have these little spurts of improvement in our training, and we say to ourselves, "Now I'm learning!" But, that's not true. That's when the time you spent practicing on the plateau just "clicks in" and you have the spurt upwards. Without the time on the plateau and without the time practicing, you would never have had the spurt upwards. Even in intellectual work, the same is true.