Yesterday I filled up my gas tank. See, okay, I'll tell the whole story. I just got back from Spain, and had to work yesterday at 8 am forty miles away. Ugh. So I left very early to get there on time. There was a ton of construction and traffic, so I thought I'd be late. Nope, there at 7:30. I had about a half tank of gas, so I went across the street to fill 'er up while I waited. I had half a tank. My tank is ten gallons. I put 5 gallo...