it's funny, the episode' very first image is Charlie waking up as they bring Claire back into camp, but it's not an eye-opener scene. Funny that they would skip a perfect opportunity.
Amnesia – the most popular trope there is.
Ethan's casual cruelty and his seemingly superhuman strength… Are they products of his and The Others' affiliation with Jacob and/or the Man in Black?
Sometimes it's hard to tell whether the character' actually experiencing a memory, when we see a flashback during the episode, or if it's just insight into the past of the character. This is one of the rare instances we actually see the character (Charlie) react to the flashback that has just played. Specifically, Charlie remembers getting sick while trying to demonstrate the copy machine. He then reacts in disgust to the memory in the present. That doesn't seem to happen very often.