There is a saying in combat sports, probably originating in boxing, that plans and strategy are all well and good until you get punched in the face. Then the best plans fly out the window.
Being able to keep to a game plan, or intelligently change it, in the face of stress takes experience and self-knowledge. Of course, the former begets the latter. It’s the same thing in CrossFit. The face punch is the first round of a WOD, or its equivalent. How many times have you started a WOD with a mental strategy in place, only to have that strategy fly out the window after the first round and not be able to keep to it. Probably a lot. The more experienced you are, the better you will be able to plan out a WOD, as you will know yourself and your abilities better. But, and this is a big ‘but’, CrossFit is pretty unique in that you are often doing a WOD for the first time. And then, it’s like getting punched in the face all over again. The unknown has a pretty hard fist.