I actually think it's part of human nature to think in a black and white manner. Like it's built into language (this is part of the theory behind ACT therapy, which I don't purport to actually understand!). If I say hot, one of the first things that probably jumps to mind is cold. The trick (as I understand it), is to hold both the thing and its opposite (the black and the white) in mind at the same time, while avoiding being drawn directly toward either one.

So if the thought is that losing flexion = failure, a middle ground response might be that physiotherapy is a work in progress, that there is something incorrect about the exercises your therapist is recommending, etc. It's useful to think in shades of grey because it opens up possibilities. We become more able to respond, rather than react in a knee jerk fashion.

I'm not sure if I'm articulating this very well. Probably because it's more theoretical than practical for me at the moment!