I've shared this with people before, but a friend of mine brought it up again so I thought I would share it with you. I'm not good at telling stories, so I'll just tell you what my son told me one day after school. Keep in mind he's 4.
So I picked him up from school one day and asked what he did that day. Usually he can't remember, even though he just left school, so after a long pause I restated that fact. He then went on to explain that he can't remember what happened at school because of the memory wolves. He went on to explain that whenever you forget something it's because the memory wolves ate it, and if you don't get it back by the time you go to sleep then it's gone forever. If that alone isn't pretty neat to think about he went on to explain that the memory wolves have pets that are worms and they raise them to become new memory wolves. Also they are aliens, possibly from another dimension, and they travel through a wormhole.
Part of the last bit was my influence as we talked and speculated on how they got from space to us, and I think that's why he decided they have worm pets (because he doesn't understand what a wormhole is) but still, this kid has some crazy imagination.