Episode 5 of "Lost"
s01e05 White Rabbit

Jack is near delirious from lack of sleep and struggles to overcome the haunting events that brought him to Australia and, subsequently, to the island. Meanwhile, Boone gets caught in a treacherous riptide trying to save a woman who went out swimming. A pregnant Claire's health takes a bad turn from lack of fluids, and a thief may have stolen the last bottles of water. Veronica Hamel guest-stars as Jack's mother, Margo. Also, Jack (Matthew Fox) flashes back at 12 years old, to find himself on the playground in an altercation with a bully,who ultimately beats him up, and later learns a life lesson from his father.