Whatever happened, happened. This is what Faraday says. He is right too. It seems there is a lot of speculation among fans as to what this means. This is my definition as far as I can explain. Forget everything Doc Brown ever taught you. In the Lost universe there is no timelines skewing into tangents. Events that we see in the past are what happened in the past and are all that ever could have happened in the past. It is based on a theory called the Novikov self-consistency principle. http://en.wikipedia.org/wiki/Novikov_self-consistency_principle The theory dictates that although time travel is possible and that a time traveller may be able to take part in past events they are unable to change events. It asks questions about free will which I will not get into here, but remember Charlotte remembered Daniel from when she was younger. He hadn't gone back in time at that point so its proof that that event had already occurred. Our losties are not changing the past of the island. They were always a part of it.