Okay, but it’s not about the real you. It’s about a version of you who’s only ever lived inside a windowless room and so has never seen what happens outside. Something enters the room. Are you able to determine whether or not that thing existed before it entered? Are you able to determine whether or not that thing will continue to exist after it leaves? Are you able to determine what it was or will be doing outside?

Okay. Presumably someone has to bring me food and drink and take away my waste. Do they come in to the room or push it in through a hatch. Do we talk - can I talk? Has this gone on since I was born, or how old was I when I was imprisoned here? Do I have access to books and videos and music? Do I know why I am imprisoned here? Is it for ever, or indefinitely or for a fixed term. All that makes a difference, doesn't it?