What sadistic programmer invented CSS?
No, I get that the browsers interpret "the rules" differently. I've excepted (or just ignore IE6 for personal projects). I get the syntax. I was having an issue with "optimizing" the code so rules aren't repeated. Sometimes layouts vary between so that you can't help but have "divitis" or "classitis", especially since most browsers can't support CSS3 selectors. Or if you try to not repeat rules, it becomes hard to track down what is controlling what. I'm not making sense.
Basically, I try to follow the advice of tutorials and books, but they always show the easiest layouts.
Either way you can't win.