This is too good a story not to share it with you. The tl;dr version of it goes like this: a man has a brain tumor, loses his memories, gets surgery, and regains them. However, as is often the case with tl;dr versions, this does no justice at all to the story, which is both fascinating in terms of its content and a very compelling read. Just to give you a little appetizer, here's how he describes the moment when his memories start coming back to him:

They began to pour onto the neural highways of my brain like a torrential summer rain. I couldn’t stop them. Their onslaught was merciless. Evenings were the most intense, as the steroids that reduced my cranial swelling kept me wide awake. With little else to preoccupy my mind, my flashbacks were largely uninterrupted. A retrieval and indexing process began to occur spontaneously, from the moment I left the operating room. I experienced memories as moving pictures, or flashes of light, illuminating a football stadium’s worth of information all at once.

Now go read the whole piece; it's well worth your time.