So I'm watching the whole series again, and I've got to tell you--now that I know to look out for them, the little clues and double entendres are agonizing. Here are just a few examples:
John Locke works for a box company. Boxes are a huge theme in all of JJ Abrams' work and especially in LOST. First we have Rousseau's music box, then Shannon mentions the plane's black box, then of course there's the "box" somewhere on the island which Ben says would give you whatever you wished for or something. Then of course, there was that emotional episode where Sayid was being tortured by his former torture victim in the flashback, and she tells him about the cat she rescued from a box full of fireworks. I'm pretty sure that, given this show's abundant other allusions to quantum physics, this box thing is a reference to Schrodinger's cat (especially that last example). What could it all mean?
In "Orientation," when John Locke and Helen are talking after the support group meeting, their conversation goes like this:
HELEN: Oh hell, you just said everything I've always wanted to say in there. Most of the time I want to stand up and scream: get over it, freaks.
LOCKE: Well, why don't you?
HELEN: I have to keep a cork in. Once I get all hot and bothered there's no stopping me. I guess you won't be coming back next week, huh?
Did you see it? "I have to keep a cork in." A reference to the cork in the island that has to stay in, methinks!
Let's see, what else? Oh yes, near the end of Season 1, when Rousseau and Jack and Kate and Locke and Arzt arrive at the Black Rock, Hurley is looking at the ship and wondering how it got so far inland.
HURLEY: How exactly does something like this happen?
DANIELLE: Are you on the same Island as I am?
HURLEY: I guess that explains it.
Whenever we hear a line that sounds slightly out-of-character or a little cheesy and unnecessary, we can be sure there's a reason for it (like when Jack said "I'm intense," explaining why he was running up and down the stadium--"intense" here meaning "in time"--see The End/Theories). The meaning of "Are you on the same island as I am?" seems pretty clear: the writers are toying with the idea of the show's reality being split, or everyone being in their own universe, having their own baggage separating them from the rest of the group, stranded on their own island. Rousseau wouldn't normally say something this comical, though, so there must be a reason she said it. I don't know anything about the philosopher Rousseau, but does anyone want to give a stab at why Rousseau's name is attached to this statement?