Freeway Driving

When driving on the freeway, stay right except to pass. This rule was drilled into me when I learned how to drive. How is it that not one other driver apparently learned it? I mean, a long road trip down to California, and you see people who stay in the leftmost lane regardless. WHY?

Did a quick trip down to see my parents this evening, same issue. The slow lane is mostly clear, and the passing lane is filled with folks driving slower than half the folks in the slow lane. ARGH!

Sometimes I think there can't be so many stupid drivers in the world... but then I remember that it doesn't require a driver to be stupid all the time to do stupid things. Just a moment of stupidity per driver can account for most of the stupid acts I witness each day.