“It was the hardest damn book I ever wrote,” Lewis said of his Silicon Valley-themed 1999 book, The New New Thing, at a conference Thursday hosted by online file-storage company Box in San Francisco. The book focuses on James Henry “Jim” Clark, a well-known entrepreneur in the Valley who co-founded Silicon Graphics, a maker of 3D graphics computer workstations, and Netscape, the maker of one of the earliest Web browsers, among other companies.

See also: Silicon Valley’s $585 Billion Problem

Lewis, who moved to the Bay Area in 1997 just as the dotcom bubble grew, said, “I found Jim Clark and I thought I could write a story about this place through him.”

“The reason the character so embodied the industry at that time—he was always destroying the thing he had just done, he was never appreciative of anything,” he added.

For Lewis, who has since written several hits including Moneyball, The Blind Side, and The Big Short, it was exactly that restlessness that made writing The New New Thing incredibly challenging.

Get Data Sheet, Fortune’s technology newsletter.

“He never got attached to anything—when a character never gets attached to anything and doesn’t actually really care about something in a really deep and emotional way, it’s very hard to make sympathetic to the reader,” he said.

Lewis’ view sharply contrasts with that of Hollywood, which seems to have a growing appetite for stories about Silicon Valley and the tech industry. “There’s really a question of, ‘How did we get here?'” Christopher Cantwell, one of the creators of AMC’s Halt and Catch Fire television series, said at Fortune‘s Brainstorm Tech conference in July when asked about the recent flurry of shows and movies about tech entrepreneurs.

To Halt and Catch Fire executive producer Melissa Bernstein, these examinations of history “may provide some insight into where we’re headed and why,” she said.

See also: Why We Can’t Stop Watching Movies and TV Shows About the Tech Industry

But Lewis appears firm in his newfound reversal of interest in Silicon Valley’s characters. Writing The New New Thing was such a turnoff that he swore he would never write another book about Silicon Valley again, he said on Thursday. Nevertheless, he did write another book about technology, Next: The Future Just Happened, which was published in 2001. The book chronicled a handful of case studies about the power of the Internet, including that of a teenager who made a fortune trading stocks by posting comments in online forums to influence the market, and TiVO, one of the first digital video recorders.

Lewis didn’t mention Next during his onstage conversation with Box co-founder and CEO Aaron Levie, though its focus on the impact of the internet and the book’s characters didn’t have much to do with Silicon Valley’s culture and people.

Lewis’s next book, due out in December, is about the story and work of Amos Tversky and Daniel Kahneman, two Israeli psychologists whose work focuses on the error of human judgement.