I've been on medications to treat my depression and anxiety for roughly 20 years. I'm not sure if they actually contribute to any of the problems listed below, but I suppose anything is possible.
For many years, I've had trouble getting a grasp on certain topics; mathematics, science, finances, politics, just to name a few. Someone could sit me down and attempt to explain certain aspects of these things until they're blue in the face and I won't have any better understanding of them. It can leave me feeling rather brainless and frustrated.
Then there are the many moments where I struggle to remember things that were on my mind literally seconds beforehand, only to draw a blank when it comes time to mention them. The same applies to items that I had misplaced shortly after putting them down.
I also have a hard time convincing myself that I've actually done something or done it correctly. For instance, I may have to check to make sure I've locked the door or turned off the oven multiple times before I can feel 100% confident that it's actually been done. This can be especially exhausting...