Tired from driving all day!

I never understood how someone could get so tired by just driving, but I know that there is a real scientific explanation behind it. I'm sure it has something to do with all the mental focus, and the physical control over the car. But honestly, you've been sitting for hours. You get out of the car and you're tired? Where is that fair? I've been exhausted ever since I got home, and all I can think about it crawling into my bed and passing out for a few hours. I'm so tired! ... From driving!! That's so wrong!
Aside from that, I'm having a really hard time wrapping my head around the fact that today is Friday. I keep thinking that it should be Sunday or Monday. I saw a thing for True Blood earlier tonight, and I got all excited because I thought it would be on tonight. Disappointment! Instead, I didn't watch anything too interesting, and sat on the sofa, getting more and more tired as every minute ticked by on the clock.
Almost 10 pm.! Time to go to bed!!