[FFRefresh]

On examining the negative thought patterns, I think there's at least a couple parts to it:

1. If you very much believe no amount of physical health interventions will have any cognitive effects, then it seems like the probability of you sticking with any sort of health/fitness routine is very low. If in fact, health/diet/fitness DOES have positive cognitive effects (it's been proven scientifically and there are tons of anecdotes), you may end up depriving yourself of a really great thing for improving quality of life and cognition. So examining the possibility that your cognition is not doomed and immune to physical health interventions could greatly increase the odds of improvement.

2. In 2 of your examples, they were social situations. In my experience, negative thought patterns can definitely impact that. I'm saying this somewhat loosely, as I'm not an expert, but have done research in the past on this: Thoughts can trigger bio/physiological responses in the body/brain that can definitely impact cognition.