It's the things in boxes that I completely forget about. There are standards for housekeeping like if you haven't been in a box in two years, just throw it out because obviously you don't need anything in there. Easier said than done for some of us! I have learned to simply write on the outside of the box. Yes, there is a use for thinking on the outside of the box
I have an amazing memory and recall about what fabric I have, but when I go through it, I'm constantly surprised by something that I have forgotten/has not been on the forefront of my thinking or found while I was looking for something else.
I do have a friend who periodically buys the same fabric more than once -- and with the same amount of enthusiasm each time!
My memory nemesis is for putting things in a safe place and them completely utterly erasing from my mind where that place may be... Sometimes it takes years to find something.