At my job, I negotiate contract terms quite a bit with suppliers and customers and the last several weeks have been particularly busy because of the end of the year. So as a result I've had quite a few teleconferences with various legal people from other companies recently and there been lots of negotiating & maneuvering and polite arguing. For the most part I like doing this a lot and I've seen very clearly how just about everything that appears to be set in stone can be made flexible with enough pressure or financial incentives (no, not bribery or extortion).
However, this past week I started to argue and debate more than I should with people providing services outside of my job and I've learned it just isn't worth it. When our web hosting company basically increased our rate slightly, I launched into an epic email struggle with them in which I was digging up old email and pounding them for being inconsistent. You shouldn't just sit back and do nothing but the amount of energy I put into this was way out of proportion to the benefit I got. Something similar happened when our apartment manager wanted to take up some of our closet space to install a new drier vent for the people below us and I had a big telephone showdown over the terms of our lease about whether they could do this. Again, for the amount of energy I spent on this (and for an apartment we're going to be leaving in several months) it's just not worth it.
I also appreciate in the John Adams biography I'm close to finishing that in Adams older years he became less feisty and pugnacious and saw this as the effects of accumulated wisdom. Similarly, his penpal Thomas Jefferson--despite being a lawyer, president, etc--actually refrained from arguing with people directly at all. I believe he didn't find it dignified. Finally, on the presidential theme, it's interesting to see how Bush Senior and Clinton have developed a good friendship over the years after their bitter presidential race and they've united on common causes. I like that. It seems wise and the right thing to do.