The on-and-off relationship of Lisa’s parents ended in an unintentional pregnancy.

It was the spring of 1972. Steve Jobs was in his senior year at Homestead High School, in Cupertino, California, and he’d just met Chrisann Brennan, a junior. On Wednesday evenings, in the high school quad, Chrisann would assist a group of friends who were making a claymation film. On one of these evenings, seventeen-year-old Steve approached her with a sheet of paper in his hands.

He’d typed out the lyrics to Bob Dylan’s “Sad-Eyed Lady of the Lowlands.” He handed Chrisann the paper and, strangely enough, told her to return it to him when she was done. He returned on subsequent Wednesdays, holding candles between takes for Chrisann so that she could add to drawings for the film.

Thus began Chrisann and Steve’s on-again, off-again relationship. It would last nearly six years.

In that first year, they fell in love. One of Steve’s biggest gestures was to stand up to Virginia, Chrisann’s mother, who was affected by paranoid schizophrenia and was becoming increasingly unhinged and harsh. She’d started telling the neighbors that Chrisann had intercourse with dogs and had accused her daughter of playing the recorder because it resembled a penis.

In the summer, Chrisann and Steve moved into a cabin together, paying the rent with the money Steve and his friend Steve Wozniak earned from making and selling “blue boxes” – illegal devices that, when held up to a phone’s receiver, emitted a series of tones that fooled phone companies into putting calls through for free.

In the fall, Steve left for Reed College in Oregon. But he was directionless, and he dropped out after about half a year. Chrisann, meanwhile, had begun dating someone else, and the relationship fell apart without much conversation.

When Steve realized that Chrisann had essentially dumped him, he was deeply upset.

About two years later, they got back together, and Chrisann started working in the packing department of the nascent company that Steve had started with Wozniak – a company they’d named Apple.

But Chrisann was unhappy. Indeed, she’d been planning to leave Steve, who was temperamental, but an unintentional pregnancy put a kink in her plans. Unbeknownst to her, her body had rejected the contraceptive she was using, an intrauterine device.

When Steve found out, he was furious and ran from the room.