Shoot man, I used to sit in my backyard watching my dogs and write out G-code for my oldest cnc mill and I'd compute the trigonometry in my head. I can barely do anything anymore. Doc says it will be 6 months until my brain gets back to normal.. Cancer is bad , Chemo is the killer of the bad cells and also those we need to figure stuff out...I dunno, my Mother died from my same cancer 1 month before I got my diagnosis. Dying is in the future of all of us,, Let me think clearly before I take the dirt nap.Dull brain is pretty awful..