Sometimes I find myself when I’m working on day to day tasks that it helps my mind when I take a break and practice martial arts for a few minutes, and then get back into it. It really helps break the monotony, and sends my mind and energy in a totally new direction. This, in turn, helps me improve my focus on the tasks I have on hand.
I’ve heard some of my students actually practicing their Kung Fu techniques at work, when no one’s watching, or if they have downtime and some privacy.
When practicing martial arts becomes its own reward, you have just reached a new level of your relationship with martial arts. You are finding peace in your practice.
Just like with any discipline, practicing can seem tedious, boring, undesirable, because we would rather have quick results. Often times, having a physical goal to achieve, such as earning a belt or getting ready for a demonstration or competition is the impetus for practicing without being told to.
But when you come to the place of just practicing because it feels good to practice, that practicing is fun and its own reward, you have started understanding martial arts in a way very few people understand. You have made an intimate connection with it, where the reward is completely intrinsic. This is where you are no longer separated from martial arts, it is literally a part of you, a part of your essence.
It takes most people a while to arrive to this place. It takes a series of tangible accomplishments and achieved goals. So people are indeed nurtured towards this path. If they are of the few who actually get to this point, chances are, they have a life long relationship with their martial arts practice.
Now if you’ll excuse me, I’m going to run through a form! 
Henry Rollins touched on some of this in his ‘Iron’ essay!