So why does CSI still confuse me?

I now have a 42 inch screen on my TV. I thought for sure once I could see things more clearly I’d understand what was going on.  Yet I still find myself halfway through CSI wondering what the hell is going on and why everyone thinks the little purple dot is significant.  Sigh…maybe it wasn’t the size of the screen after all.  Maybe I’m just not meant to understand that show.