Truman went from human to content when the show started to get into it's older stand point and became more and more famous as the years went by, especially when the show is running 24/7 all year around.
"We accept the reality of the world with which we are presented with" was the statement that Christof make when he is talking to sylvia over the phone on a TV interview. This and the allegory of the cave are somewhat the same as well as different because the allegory talks about the prisoner being freed and telling his friends but they don't understand him. Truman is the prisoner in Christof's world and the allegory of the cave lines up perfectly with this movie except the part where the prisoner goes back to tell his friends of his amazing discovery.
I think personally, that Seahaven is the place where it would be a dream place but reality is not a dream place, and the prisoners will eventually find out the "Truth" of it all and escape the place where they are controlled and manipulated. The real question to ask is that "what is normal?" Is it a house wife and kids? Is it having everything you want? We think of normal being just average and the reality is that there is no normal because we are all different and not all the same. Some of the benefits of living in a place like Seahaven is that everything is perfect and everything goes right as well as everyone being