Boltzmann Brain: The Rumour That You Just Appeared With a Lifetime of False Memories

You open your eyes, see a room, remember your name, family, school, past days and the history of Earth. But what if all those memories appeared at the same moment as your brain? No one implanted them and no computer built a false world. In the Boltzmann Brain story, a universe that has become extremely old and nearly empty can, after a vast amount of time, randomly form a complete brain for a moment. That brain feels it lives in a world with a past, even though the past exists only as memory inside it.