How Is a Memory Stored Inside Your Squishy Brain?

Memory is one of the strangest abilities you possess. Your brain uses an incredibly complex biological system to preserve moments from your past that no longer exist, allowing you to revisit experiences from years ago. But memories are not always recordings of reality. In fact, every time a memory comes under the spotlight of your attention, it can melt and change a tiny bit. What exactly is a memory, how is a moment in time stored inside your brain, and why does remembering something slowly rewrite the story of your life?