A 10,000 mile walk, begins with a single step and continues one step at a time.
Jiu-jitsu puts you completely in the moment, where you must have a 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.
Don't be rushed, be sure.
Our fears don't stop death, they stop life.
If you are ready to die, then you are ready to live.
If you are not comortable to deal with an opponent 50 lbs heavier than you, there is something wrong with your Jiu Jitsu.