Forgetting and remembering childhood
Memory relies a lot on context clues. Sometimes we have a hard time remembering anything specific from our childhood, because so much of us is different--you're literally seeing the world from a completely different perspective, from about 3 feet off the ground. It can come back when you see things you haven't seen since then, like a favorite toy. That's what makes nostalgia such a heavy drug--it can be very effective for bringing back pleasant childhood memories. Of course, depending on your childhood, what you get could be really horrible memories.That toy could have been a birthday present, and you forgot this because all you could remember about that birthday was how your dad ruined the whole day for you.