@neversosimple One of the things that cause mental exhaustion for me and that I'm just starting to get a hold of are sounds. Up until this year I've never really noticed, how much external sound affects my energy level. I've mostly noticed how loud everything was when there was suddenly no sound. A classic is the neighbor who is mowing the lawn and then suddenly stops. Even though I don't "notice" the noise, my body ist still reacting to it. I'm tensing up.
I also never liked to go grocery shopping. There's more to that, but noise also is a big one. Since I'm using earplugs or earphones I can navigate the store a lot better.