On our way up to Greenwood, I experienced something totally new. I was "that slow car."
Being a consistent 8 mph over the speed limit driver, I often get stuck behind "that slow car." You know - it's the car that is driving significantly slower than the rest of traffic, and when you get stuck behind it you will get passed by two cars and three semis before you can go around it. Whenever that happens to me, I sit there fuming and thinking to myself, "You moron - why can't you drive the speed limit?!?"
I learned that sometimes, the reason they aren't driving the speed limit is because they can't. Maybe the 21 year old truck they have to follow for 3 hours physically cannot drive faster than 63 mph, unless they are going down a hill, in which case they might top 67.