I had memory issues while on pred. Once I was off they are like all my other side effects, they all go away slowly but surely. I also have had residual memory issues from some of the drugs used to knock me out for scopes and surgeries. I think I read once (don't quote me on this as it may have come from someone else's belief with no medical proof) that it takes 1 month to get over the memory loss effects of 1 hour under anesthesia. With everything I've had done in the last 6-12 months that would explain a lot. I might get back to my old brain in the next year.
You also get the bonus effect of what my friends call mommy brain. They tell me it has been medically proven to exist.
I have found that doing brain teasers/puzzles and focusing on working/using my brain has helped me to regain my mental function faster than I have in the past after being knocked out. I have also found that when I am dehydrated my mind is definitely not as sharp as it normally is so perhaps that may be something else to consider.