I like the description of Cross as a dirty TT. CX does require a great deal of thinking though. Lines change, sometimes on successive laps, and one has to pay a great deal of attention to this. You've also got to size up your opponent and his strengths and weaknesses. If he's better at riding the sand or navigating twisty stuff then you better flog yourself to get to those obstacles first or he's going to get away. Figuring out whether to run or ride, or remount/dismount early or late can be a huge difference. I made some sweet passes this year by making the right call. I also had some last lap mental lapses, due to fatigue, that cost me. I've seen quite a few races won by guys who used their brains and defeated someone with a bigger engine. Being forced to use my brain is my favourite part of cross, makes it hurt even more though!