Concentration is the ability to think about absolutely nothing when it is absolutely necessary.
I've led a school whose faculty and students examine and discuss and debate every aspect of our law and legal system. And what I've learned most is that no one has a monopoly on truth or wisdom. I've learned that we make progress by listening to each other, across every apparent political or ideological divide.
We say no to lots of things that would please us. I would like to punch people every now and then, but I don't. I would like to have something for free rather than pay for it. I would like to skip to the front of the line... I don't mean to brush aside the taste of meat, which is a powerful attraction. But its power is not without limit.