One of the problems I have noticed most with my aging brain is my spelling. I used to be able to spot a misspelled word immediately and I rarely ever got a word wrong when I wrote. Now I find I think I have written something correctly only to go back later and find many errors.
I also can't remember the correct way to spell things anymore. Every time I write about Silver Gate, Montana, a place I have frequented since I was a child I have to ask myself--is it Silver Gate or Silvergate? I just can't remember. And it is the same with names, when I write about Keira, I have to stop and think, is it Keira or Kiera? She is almost three years old, you think I would have learned it by now. And even when I think I have written it right, I go back later I find I wrote it wrong.
It is vey humbling to have your brain pull tricks on you, especially when it leads you to believe you have done a good job, only to find you left something in, you intended to have out or vice versa.
I have been making videos of my pictures and putting them on You Tube--a good game would be to go through them and count all the mistakes...but I doubt anyone will even watch them, let alone be interested in seeking for errors. But to me, it is very humbling and makes me realize I had better put a speed up on all the projects I have left to do, before my brain completely turns to mush.