Steve Jobs called long-time rival and Microsoft co-founder Bill Gates "unimaginative" and not really a product person, according to a biography of the deceased Apple chief executive.
"Bill is basically unimaginative and has never invented anything, which is why I think he's more comfortable now in philanthropy than technology," Jobs told author Walter Isaacson.
"He just shamelessly ripped off other people's ideas.
"He'd be a broader guy if he had dropped acid once or gone off to an ashram when he was younger".
The biography "Steve Jobs" by Isaacson hits bookstores on Monday, but was released earlier-than-expected on Apple's iBooks and Amazon.com's Kindle late Sunday.
Gates, for his part, was slightly envious of Jobs' mesmerising effect in people but found the technology icon "weirdly flawed as a human being."
But Gates, despite his differences with Jobs, enjoyed his frequent visits to Apple's office in Cupertino, especially when he got to watch Jobs' interaction with his employees, according to the biography.
"Steve was in his ultimate pied piper mode, proclaiming how the Mac will change the world and overworking people like mad with incredible tensions and complex personal relationships," Gates said.
Isaacson, in an interview with "60 Minutes" on CBS on Sunday, provided more insight on Jobs' personality and character traits.
Isaacson's biography reveals that Jobs refused potentially life-saving cancer surgery for nine months, was bullied in school, tried various quirky diets as a teenager, and exhibited early strange behavior such as staring at others without blinking.
While Jobs revolutionised multiple industries with his cutting-edge products, he was not the world's best manager, Isaacson said.
Jobs changed the course of personal computing during two stints at Apple and then brought a revolution to the mobile market but the inspiring genius is known for his hard edges that have often times alienated colleagues and early investors with his my-way-or-the-highway dictums.
"He's not warm and fuzzy," Isaacson said in the interview. "He was not the world's greatest manager. In fact, he could have been one of the world's worst managers."
"He could be very, very mean to people at times," he added.
Jobs loved to argue but not everyone around him shared that passion, which drove some of his top people away. While his style had yielded breakthrough products, it didn't make for "great management style," Isaacson said.
In one of the more than 40 interviews that Jobs gave the biographer, the technology icon said he felt totally comfortable being brutally honest.
"That's the ante for being in the room. So we're brutally honest with each other and all of them can tell me they think I'm full of shit, and I can tell anyone I think they're full of shit," Jobs said. "And we've had some rip-roaring arguments where we're yelling at each other."
'Few other visions'
Jobs would have liked to conquer television as well, Isaacson said.
"He had a few other visions. He would love to make an easy-to-use television set," said Isaacson, speaking of Job's last two-and-a-half years of life.
"But he started focusing on his family again as well. And it was a painful brutal struggle. And he would talk, often to me about the pain."
Jobs, in his final meeting with Isaacson in mid-August, still held out hope that there might be one new drug that could save him. He also wanted to believe in God and an afterlife.
"Ever since I've had cancer, I've been thinking about (God) more. And I find myself believing a bit more. Maybe it's because I want to believe in an afterlife. That when you die, it doesn't just all disappear," Isaacson quoted Jobs as saying.
"Then he paused for a second and he said 'yeah, but sometimes I think it's just like an on-off switch. Click and you're gone," Isaacson said of Jobs.
"He paused again, and he said: And that's why I don't like putting on-off switches on Apple devices."
(Editing by Anshuman Daga and Derek Caney)