It takes every fiber of my being to resist arguing with folks on the usual suspects: religion and politics. And it's not for the reason you might think. Sure, I hold very controversial positions (read: atheist libertarian) on each subject, so I'm bound to disagree with just about anyone I talk to. But that's not why I resist the urge, generally speaking.
I read a lot. I try to keep up with the basics in news, particularly politics, science, and other geeky things related to my career in software. It takes a lot of my time. I imagine many folks choose other things instead. Or choose to read different topics than I do. That's fine, of course.
But if all of this absorption of knowledge so far in my short life has taught me anything it is that things are always more complicated than they seem.