The world is like a ride in an amusement park, and when you choose to go on it you think it's real because that's how powerful our minds are. Many people have been on the ride a long time, and they begin to wonder, "Hey, is this real, or is this just a ride?" And other people have remembered, and they come back to us and say, "Hey, don't worry; don't be afraid, ever, because this is just a ride." And we… kill those people.
It's just a ride.