"Count to five" is a story about Jack's past that he related to Kate.
On the day of the Oceanic 815 crash, Jack was wounded in a place on his back that he couldn't reach. He convinced Kate to suture the wound closed for him, and to calm her nerves while she did it, he told her a story about a time that he was afraid, but overcame it. The story helped develop a bond between the two, and Kate used the technique of counting to five on multiple occasions.
Well, fear's sort of an odd thing. When I was in residency my first solo procedure was a spinal surgery on a sixteen year old kid, a girl. And at the end, after thirteen hours, I was closing her up and I, I accidentally ripped her dural sac, shredded the base of the spine where all the nerves come together, membrane as thin as tissue. And so it ripped open and the nerves just spilled out of her like angel hair pasta, spinal fluid flowing out of her and I... and the terror was just so crazy. So real. And I knew I had to deal with it. So I just made a choice. I'd let the fear in, let it take over, let it do its thing, but only for five seconds, that's all I was going to give it. So I started to count: one, two, three, four, five. Then it was gone. I went back to work, sewed her up and she was fine.
—Jack ("Pilot, Part 1")
The incident Jack mentioned in the pilot was shown in a Jack flashback during "The Incident, Part 2". It was revealed that Jack counted to five at the direction of his father Christian Shepherd, who was also present. Jack subsequently complained that in so directing Jack, Christian had given Jack a "time out" in front of the rest of Jack's team, which Jack found humiliating and undermining.
- Jack's tattoo had the number five.
- Counting to five was a technique that Kate took to heart, as she used it the very next day to move past paralyzing fear, when she thought Jack hadn't escaped the Monster. ("Pilot, Part 1")
- Boone was originally going to be called Boone Anthony Markham V (Called Five by the group). Being called "Five" would be almost a direct reference to "Fiver" a character in the book Boone took on the trip, "Watership Down."
- Kate counted to five as she was lowered into the Hatch by Locke. ("Man of Science, Man of Faith")
- Sawyer counted to five (one-Mississippi, two-Mississippi...) before retrieving the cash he long-conned from Cassidy. ("The Long Con")
- Jack used the story as a password that Kate could tell him when she had reached safety, so that he would know to finish with Ben. ("I Do"), ("Not in Portland")
- Charlie's "greatest hits list" contained five items. ("Greatest Hits")
- Hurley counted to five when seeing Charlie at the Santa Rosa Mental Health Institute. ("The Beginning of the End")
- Jack downplayed his stab wound to Kate, joking "Get me some thread and I'll count to five." ("The End")
- On the Season 1 DVD special features, it is revealed that "Five" was Boone's original name and that when they ran a search and replace on the "Pilot, Part 1" script, it accidentally changed this story to have Jack say: "One, two, three, four, Boone".