bjj has taught me a lot about life in general, and i've never had to take that arrogant, formal martial art composure to my life to do it. basically you excell in bjj when you start figuring out truths to our physical/mental selves.
most every beginner in bjj tries to muscle everything. this is expected because it's the only thing a person will know how to do if they don't know any moves. now a person might get by for a little bit trying to muscle things until
a) he rolls with a dude who outweighs him by 100 lbs
b) he rolls with a purple/brown/black belt
one will quickly notice that their muscles don't mean a whole lot, especially after a minute or 2 of rolling. now if you watch that advanced grappler roll with the overweight dude, you'll see him handle the guy with relative ease compared to the new guy.
bjj then becomes a process of deductions
ex) you probably have 2 arms and 2 legs just like the advanced grappler. thus you have the same capabilities of him
as you progress in bjj, these deductions will go from really obvious to much more precise
ex) the darse choke can be achieved when you increase the distance between his elbow and his hip. this can be deduced from the fact that he's weaker when his elbow is further from his hip. this can be deduced from the fact that you're stronger when you're in a ball. this can be deduced from the fact that when you're in a ball, you have more potential energy. this can be deduced from the fact that when all limbs are fully outstretched, one limb must be pulled in to initiate movement. and so on...
if you want to have a martial art that teaches you to "concentrate" then just make sure you ask WHY when you're learning the art. "why does this move work?" "why does he beat me here?" "why am i getting tired whenever i do this move?" asking WHY will probably make you think/concentrate well in any martial art. thus i believe that bjj or muay tai are optimal cause you can learn how to concentrate and learn how to smash somebody on the streets.
and that's really the goal right? i'd rather choke somebody out then show off a solid horse stance when a mugger comes...