There are a lot of theories that have crossed my mind.

The father being the mastermind is an obvious one. But a little too obvious for my liking, you know? I can't imagine Lost's creator doing anything short of a complete surprise. Maybe he'll pull a 'Usual Suspects' on us and Usual Suspects Spoilerhave 'Henry' be the mastermind. Maybe it'll be a group of their parents, such as Jack's Dad, Sun's Dad, etc.

But it's more than just that, for sure. The smoke monster thing, the way that the island has healing qualities, stuff like that just can't be 'organised' by a mastermind. There is definitely some level of fantasy and/or science fiction involved with all of this.

There are a lot of stories that we still need to learn about that a lot of people have forgotten to think about, particularly the latter of the below.
Walt's "powers".
The French girl.
The smokey monster type thing.
What the numbers mean.
The guy who escaped from the hatch and ran away.

Nobody ever brings up the Irish dude anymore. He ran away, and that was that... it can't be that simple. Nothing, as far as I'm concerned, is that simple in this show.

I often wonder just how many groups of people have come to this island.

Also, does anyone else find it not to be a coincidence that the parachute with the food etc. arrived right when Loc was trapped, and Henry might not have done anything? It could well be that the ticker actually sends food down. That's rather trivial, though, I have to admit.

I think that the final episode will involve the numbers not being punched into the computer.

But I won't pretend to know anything. I've picked a few things that have happened, but I'm more than happy to just be surprised.

I'm glad Anna Lucia is gone. She's too much of a character-drive actress, so it felt like I was watching the girl from every movie I've seen her in, rather than a character in Lost. I think they should avoid actors/actresses that play the same kind of character in all their movies etc, as it just makes you think of the actor rather than the character in the show.