Don't tell me what I can't do by theotherjosh

So far in the ALT reality everything thing we've has been drastically different. Even when thing are similar they are still largely different in big ways. And yet when Locke tells Helen what happened to him in Australia, it is word for word, moment for moment, the scene we saw in "Walkabout".Why?

I believe that we are going to see in the very near future that what we believed were "flashbacks" from one reality were actually "flashbacks" from two(or more) realities. One where 815 crashes and one were it didn't. However the two time-lines essentially happen at the same time. So it would simply be a matter of timing. Waiting until the moment the two realities converge.
So there are two or more John Lockes in multiple realities. So somehow Jacob makes a swap or "substitution", and the Locke on the Island is not the Locke we saw in last nights episode. I think that this calls into question all the "flashbacks" we have seen, and whether they take place in the ALT reality or the reality where they crash. Making LOST the type of show that can only be appreciated and understood once you get to the end and re-watch it. Almost like Memento.