If you take photos to remember something then you can have a lot of unique photos. While everyone else is chasing the perfect photo you'll have something that is actually true to the memory.
Wow, this comment just got me thinking. If I've got good at taking well composed photos, according to common photography techniques, might they have less of that time-machine, memory-jogging quality? I'd like to have both - maybe I need two sets for photos!
You take photo to forget. You let objects to save that memory for you so that you can forget. Sure you still remember some, and some pointers of images.