That quote by Rickson is one of my favorites. This is the quote in it's entirety.
"Where there's discomfort, there's fear. In these very tough positions, you're in a little piece of hell. And through this daily suffering, you learn to survive in these situations. You have to find comfort in uncomfortable situations. You have to be able to live in your worst nightmare. Jiu-jitsu puts you completely in the moment where you must have complete focus on finding a solution to the problem. This trains the mind to build that focus, to increase your awareness, your capacity to solve problems. Sometimes, you don't have to win. You cannot win. But that has nothing to do with losing." -Rickson Gracie