In 1967 and 1968, there was a British TV show called The Prisoner that supposed these questions, and painted a very dark and dystopian picture of possible extra realm beyond commonly experienced society, where unseen powers oversee and control the existence and limits of all those within their grasp. People are taken there, against their will, and not allowed to leave. People who knew something. Something they shouldn't have known. It's messed up to the point of inducing a deep state of paranoia or even schizophrenia.
You don't know how you get there, but you're there. And you can't leave. You're a prisoner among hundreds of other prisoners, but you're the only one who knows it. Or at least you think you know it. Are you really still a prisoner if you forget you're being held against your will? Existentialism aside, what if it's your environment that's taking away your sense of individualism?