For thing that I need at work, I put in my cell phone's note pad. At home, i keep a little notebook by my computer, since that's where I do my school work. Plus I make a calender for myself. As far as age or depression, my mother gave me a plaque that I have cherished for years.
It said:
The more I study, the more I know.
The more I know, the more I forget.
The more I forget, the less I know... So why study.

maybe you just have too much that you are trying to remember