Theories revolving around Jack Shephard by Joshua S. Smith

It is believed by some that LOST is an ever circling cycle of dramatic irony.Events tied to others by means of time travel of the main characters and some supporting characters. One such interesting point I have read of recently is that Flashbacks may not be flashbacks at all but flashforwards, and vice versa. Damon Lindeloff and Carlton Cuse may have slightly tipped us off to this in their interview shortly after episode 1 of season 6 in which they made a point that their goal this season is not to have maintaining "alternate realities " (a term by the way they refuse to use to refer to what is currently happening).

One such theory is that when Jack lands at LAX in 2004, it is not his child(David Shephard) that he visits at the Piano recital but Future Jack's. The reason this is, is that Jack wanted to know the name of the man Sarah was with, and she couldn't give him the name because it was him from the future. Which explains why he never found the lover's cell number because it is his own or the calls are coming from somewhere different like a phone booth.
Sarah may have fallen in love with future Jack when he secretly traveled in time to give her the power to walk after young doctor Jack felt he ultimately had failed. Another supporting scene that may lead to Jack's reasoning for visiting Sarah from the future is...when he and Sawyer are talking in the jungle right before their fight and the "incident". Jack tells Sawyer, "I had her and I lost her" as the reason for resetting everything. Now Sawyer assumes Jack is talking about Kate and Jack never denies that he is talking about someone different because at one point he loved Kate, but Sarah seems to be the one Jack is really talking about, because Sawyer kind of clues this in by saying..."If you set off that nuke and it works you and Kate won't know each other." That really doesn't matter to Jack as much as many would believe.
Another interesting point to make about David...shortly before Sarah left Jack she revealed to him that she was not pregnant and he was relieved. This may have been a test to see if she would stay with him after she was impregnated by future Jack. It is possibly comfirmed by the scenes involving Jack as an alcoholic pill popper, who attempted to kill himself but then after attempting to help someone gets hit by a car and goes to the hospital. When he is there, he is visited by Sarah who is visibly pregnant (with David in theory). They have made us believe that we have a developed timeline. But what if some of these events have skipped around? Another important point regarding his relationship with Sarah is when the secret lover is standing outside by Sarah's car, and jack asks if it is him. Sarah says "It doesn't matter who he is, it matters who you are not", possibly hinting at that without her leaving him, he will never return from the island in time to be with her because! of knowing what he had lost.
Another interesting theory was one that involved the last episode ending with a final fight between Jack and Locke. The fight would occur just before the plane crashes on the island. Which if you pay attention to the opening scenes of the pilot...1) When Jack takes off his shirt to reveal what seem to be visible knife wounds and 2) Locke appears to have a cut on his face from a punch and he seems to look at his right foot out of interest that it is moving...but if you pay attention Locke is only wearing a sock on his right foot. But the director made a point to show Locke's shoe hanging where Jack gets up from.
Another clue from the opening scene of the pilot is a dark cylinder that is laying next to Jack's head. The dark cylinder is also seen in the hands of John Locke and Benjamin Linus when they time traveled.Because of the many Egyptian references throughout the show, it should be noted that Egyptians believed that Cylinders were an energy source that influences time and space. And how did Jack know in the opening scene of the pilot the exact direction to run in when he woke up? It is because he knows exactly where he is.Jack also pulls a bottle of Liquor out of his pocket (that he could use for disinfectant?), a bottle that made it appear on the plane to the Stewardess he wanted to drink then because he needed s Strong drink, then he does something strange, he put it in his pocket before the crash. The director made a point to have Jack stop and listen when he arrives at the beach for where the crash is, so he obviously didn't hear the crash scene until he arrived at the beach! , meaning it didn't direct him to the beach...HE KNEW WHERE IT WAS!Then when Jack arrives at the beach he tells Hurley...who he supposedly doesn't know, "If the contractions occur less than 3 minutes apart, call out for me", but he never tells Hurley his name until he is running away (Probably because he forgot that he is not supposed to know Hurley yet). Later in the pilot Kate makes a point to note Jack doesn't seem afraid at all. And Jack also talks to Kate by the fire and says "I don't know your name", but the way he says it, it's like he is saying to himself, oh yeah, I am not supposed to know your name yet. Why did Jack want to go to the plane cockpit alone to get the transponder? How did he know where it would be? Why did he tell Kate she would need better shoes? Because he knew where it would be. He didn't want people slowing him down. Then when they are on the way the Smoke monster attacks, Jack saves Charlie then Jack disappears, later in the scene Charlie explain! s to Kate, "We were dead, I was dead" and then he saved me and! then he was gone.In "Tabula Rasa, Jack tells Kate, it doesn't matter what we did before this, and then says before the crash. Like he is saying before in the other time loops. And then he says we all died three days ago(Is this literal?).

When Jack is handed the candy bar in the hospital by Jacob, Jack is the only one he doesn't apologize to, because Jack is the one that was selected as the one to replace him(Which is probably why Jacob says..."Maybe it just needed a little push" when he hands Jack the Apollo Bar).
Another interesting note that may place Jack as the new Jacob is his tattoo..."He walks among us, but he is not one of us". Meaning he walks among the normal people but he is traveling through time and leading the island to it's new fate. Meaning he is the white rabbit. He Jumps to conclusions, he makes decisions that seem rash, and he leads. And he does it with some sort of understanding. He is the white rabbit that leads everyone down the hole(Which is ironic because Christian told Jack not to be a hero because he could not cope with failing, which Jack has seemed become conditioned to do).
Another interesting point...When Desmond just so happens to meet Jack in the stadium(which Jack was at trying to run out his worry of whether or not he fixed Sarah), was Desmond being a constant, and from the future? Desmond intuitively guessed that Jack was worried about a woman (or was it just knowledge of that moment, traveling in time with future Jack?). Then Desmond hypothetically said maybe Jack didn't fail to fix her(Because future Jack was doing just that, while Desmond was talking to 2001 Jack). Desmond also mentions "almost being a doctor" (DHARMA?). Then Desmond made a point to say "I'll see you in another life brotha".
Another interesting point about time traveling Jack...after Kate gets out of jail from her trial(when returning from Penny''s rescue), Jack somehow knew when and where she would be leaving the building. When she asks how he knew she would be there (foreshadowing), it takes him a minute to provide an explanation. Later on when Claire is taken from Ethan, and Jack is looking for her, Jack gets knocked out by Ethan and then when he wakes up dizzy and tells Kate..."I'm not going to let this happen, not again". Like he knew something bad was going to happen to Claire if he didn't find her.

These are all complex situations that are hard to tie in with theories but maybe I have found something solid.