Once upon a time, a person was offered a choice by a force infinitely their greater. Either they could remain as they are, continuing their life as though nothing had happened, or they could get a chance to experience a different life altogether, abandoning their old life in the process. This person, for some unknown reason, chose the latter.

At this stage, you're probably thinking "Great, I'm going to get to experience another life!" and whilst that is technically true, there is one small problem. Namely, that person? That isn't you. The simple truth is, the force couldn't just take them away and leave an empty hole where the person once was. It needed to fill the gap lest the being's peers figure out what it had done. It needed a replacement.

Whether because of fate or simply plain old bad luck, you are it. Whilst you were sleeping, your soul, or spirit, or consciousness or whatever you want to call it was pulled away, sucked out of your body, dragged away and away until finally, you were shoved into the empty, sleeping shell of the one who'd taken the opportunity to begin with.

As of right now, you are still asleep, and by the time you wake up, you'll have forgotten everything about the actual transfer event. How much your other memories, how much your personality and spirit have been influenced by the ordeal, that yet remains to be seen, but as of right now, there is a more pressing question to consider.