Strikes close to home. 8 years ago I was in a bike accident that took me out for 4 months. I instantly felt dumber. The headaches became a fact of life, and the need to get out of the house early in the day to avoid brain fog creeping in became a routine.
It... sucks. I've still progressed my career and made significant strides, and come to appreciate things that I never would have noticed if I kept on my previous trajectory, and while I don't think about it much anymore, for years it ate at me.
Do you still have headaches?
I was also in a bike accident that resulted in brain trauma (not a stroke), and yes, still get headaches 5 years later.
But it does get better with exercise. I was able to reduce weekly headaches to about 1/month.