What we do know is that we, the Lost couch potato castaways, saw Ben turn the wheel hidden in a room below the unfamiliar Dharma Orchid Station, the sky white out and the island vanish.
All of this culminated a time-travelling, Emmy-nominated season of past and future stories that split up the Lost tribe - rescuing some people after 108 days, leaving some to linger on the island, and killing others.
If none of the above makes sense to you, yes, it's too late to pick up Lost now. That's what DVDs are for.
For four seasons, viewers have flashed back and forward through a maze of puzzles.
When the penultimate season of the hit show premieres tomorrow, executive producers promise that answers will come our way, but it might take fans a moment to notice - because the fifth season takes viewers on yet another narrative roller coaster.
"Although the show occupies the same world, we're always driven not by rules but by what is the best way to tell stories in any given season," executive producer Carlton Cuse said.
"Viewers will have to adjust to a little bit of a different mode this year, but we think that in that challenge also is the excitement that keeps Lost fresh."
First, we got to know our castaways through flashbacks of events that happened before Oceanic Flight 815 crashed in the South Pacific on September 22, 2004.
Then, viewers caught glimpses of them in the future, a future that revealed that some of them were rescued.
The ground-breaking storytelling then took another turn when viewers became privy to future events that predated the future they'd already seen.
This season, the flashbacks and flashforwards still will exist, but another storytelling approach will dominate.
And in classic Lost tradition, the producers won't explain what they're doing ahead of time.
"We're really happy with the scripts that we're writing, but at the same time, there's this complete sense of fear and second-guessing in terms of whether or not the audience is going to groove on what we're doing," co-creator and executive producer Damon Lindelof said.
"The show is taking on a new model in terms of the way we tell stories and finding a balance between what's happening off the island and on the island.
Are the characters having an emotional experience no matter how crazy it is? That's the part we're focused on."
The first seven episodes will focus on the aftermath of Ben's (Michael Emerson) pronouncement to Jack (Matthew Fox) in the last scene of last season that the Oceanic 6 must all return to the island, including Locke (Terry O'Quinn), who has died.
Jack's challenge is to enlist the rescued castaways to go back, but that will prove tricky as he and Kate (Evangeline Lily) have broken up; Sayid (Naveen Andrews) is trotting the globe, killing people for Ben with Hurley (Jorge Garcia) in his custody; and Sun (Yunjin Kim) has gone rogue.
Viewers also will see what has happened to Penny (Sonya Walger) and Desmond (Henry Ian Cusick) after she rescued him and learn how Locke left the island and later died.
The story of Walt (Malcolm David Kelley), who left the island two seasons ago, will continue, although his father, Michael (Harold Perrineau), died attempting to return to the island in the season finale.
Sawyer (Josh Holloway), Juliet (Elizabeth Mitchell) and Charlotte (Rebecca Mader) survive on the island.
"The conventional thinking might be that we're going to spend the entire season telling the story of how and if these characters are able to make it back to the island," Lindelof said.
"That's not what we're doing. Not by any stretch of the imagination."
Because death on Lost is a relative term, as Cuse likes to say, fans can expect to see more of Jin (Daniel Dae Kim) whether he survived the freighter explosion or not; the mysterious Christian Shephard (John Terry), whose death caused his son, Jack, to be on the doomed airliner; and Rousseau (Mira Furlan), who was shot to death.
The ageless Richard Alpert (Nestor Carbonell) will pop up again.
Although fans do not know what happened to Claire (Emilie de Ravin) - the actress does not have a regular role this season, mind you - she will appear during the season.
For that matter, so will Vincent the dog, the only character the producers have committed to keeping alive for the entire run of the series.
•Lost screens on TV2 at 8.30pm on Wednesdays.
