Everyone wants a good memory but we don't often ask ourselves what memory is for. Let's begin our exploration of why memory is important and how it works with a little memory test: Do you remember what you learned in class last Wednesday? How about what you got for your last birthday? One of the greatest mysteries of the human mind is why we remember some things, but not others. Why is it that we might have perfectly vivid memories of what we did on vacation two years ago, yet we struggle to remember details from what we learned in class just last week? What happens in our brain that turns some moments into lifetime memories, while others are lost, forever forgotten?