Anne Lamott in Bird by Bird:

But I still encourage anyone who feels at all compelled to write to do so. I just try to warn people who hope to get published that publication is not all that it is cracked up to be. But writing is. Writing has so much to give, so much to teach, so many surprises. That thing you had to force yourself to do—the actual act of writing—turns out to be the best part. It’s like discovering that while you thought you needed the tea ceremony for the caffeine, what you really needed was the tea ceremony. The act of writing turns out to be its own reward.

It’s about writing, but applies to anything hard, including jiu-jitsu. Just as you’re likely never going to have a book published (besides a Kindle self-publish), you’re likely never going to win a jiu-jitsu competition. But it’s about the process, not the outcome. Some results from learning jiu-jitsu may be better fitness, more confidence, self-defense skills, but it’s the training that’s the point.