I've once read a theory in a psychology book. This theory said that you never lose anything, you intentionally put it somewhere you won't be able to find it for reasons you're not clearly given to know. Same goes for forgetting appointments and so on. It's a self-defense mechanism or a mechanism to erase inner fears. I don't trust this theory much, but it helps a bit to know there must be a reason for forgetting or losing something
I forget where I put my things, then I find them when I don't need them anymore. Countless times I lost keys, books, other objects, and a couple of times money! I forget to do what others tell me and I often have to repeat that I have to do something mentally to not forget it later. For other things, as facts or events, my memory is perfect. I can always remember. Maybe, thinking about it, there's some truth in the above theory about forgetting things
