Google: 'Don't be evil'
Marissa Mayer, president and CEO of Yahoo and former Google executive, told The Sydney Morning Herald where Google's famous "Don't be evil" mantra originated: The brain of Amit Patel, one of Google's first engineers, who was Mayer's cubicle-mate in 1999.

In Google's early days, said the Herald, the engineering team was resistant to sales hires because the engineers "feared they would be pressured into moving certain clients higher in search results listings or building products they did not want to build." Patel came up with a way to vent his worries: In a conference room where the sales team held client meetings, he wrote "don't be evil" on the white board "in this incredibly neat handwriting in tiny little letters," said Mayer.

A few years and a few hundred hires later, Google's human resources team met with Google's senior staff to brainstorm a list of company values. Paul Buchheit, the man who invented Gmail, suggested they choose Patel's warning "Don't be evil" as an umbrella idea that would cover the rest of the list. The phrase appeared in Google's 2004 IPO letter, which was later called "The 'Don't Be Evil' Manifesto."

Facebook: 'Move fast and break things'
A lot of what we see when we log onto Facebook, from "like" buttons to timelines, was created during "hackathons" — company events where engineers stay up all night eating Chinese food and building working prototypes of ideas they don't have time to pursue during working hours. For this type of scramble to reap results, the engineers have to code fast and not be afraid to make mistakes.

Which is one reason why "move fast and break things" works as Facebook's corporate mantra.

"The idea is that if you never break anything, you're probably not moving fast enough," Mark Zuckerberg told Business Insider's Henry Blodget in a 2009 interview. "You know, in college, I just built a whole lot of different things. That's just a passion of mine," he told Blodget. It's now a cornerstone of Facebook's corporate philosophy:

We've optimized so much of our culture around just making it so that people can come and build things quickly. Whether it's everything from having the right tools in the right development environment to build things quickly, to nightly code pushes, hiring the best people who have a bias toward just pushing things very quickly, very entrepreneurial. The whole culture is tuned around that. And I think there's probably something in that for other entrepreneurs to learn which is that making mistakes is okay. At the end of the day, the goal of building something is to build something, not to not make mistakes. [Business Insider]

Three years after the interview, when Facebook's users had grown to almost a billion and Zuckerberg was preparing for its IPO, the founder wrote about the mantra in his letter to potential investors. "Moving fast enables us to build more things and learn faster. However, as most companies grow, they slow down too much because they're more afraid of making mistakes than they are of losing opportunities by moving too slowly. We have a saying: 'Move fast and break things.'"

He also revealed a couple other Facebook mantras: "Done is better than perfect" and "Code wins arguments."

Apple: 'Think different'
The way most records tell it, Apple's "think different" ad campaign — the one from the late 1990s that showed photos of Alfred Hitchcock, Fred Turner, and Jim Henson with the phrase and Apple's logo — was based on a mantra Steve Jobs sought to apply to Apple.

But Rob Siltanen, chairman and chief creative officer at Siltanen & Partners, the ad company responsible for the campaign, tells a different story. "The famous 'Think Different' line and the brilliant concept of putting the line together with black and white photographs of time-honored visionaries was invented by an exceptionally creative person, and dear friend, by the name of Craig Tanimoto, a TBWA/Chiat/Day art director at the time," Siltanen wrote in Forbes after Jobs' death.

Siltanen claims that during a brainstorming session, when Siltanen & Partners was working on a bid for Apple's business, Tanimoto mocked up a few of the images and posted them on the wall:

Craig's Apple campaign seemed big and fresh in a room that was filled with classic computer shots and stereotypical celebrity photos. I loved it. But at the same time, the work seemed in need of explanation.

I asked Craig what it all meant, and he said, "IBM has a campaign out that says 'Think IBM' (it was a campaign for their ThinkPad), and I feel Apple is very different from IBM, so I felt 'Think Different' was interesting. I then thought it would be cool to attach those words to some of the world's most different-thinking people." [Forbes]

So that's the other story — that one of the most famous and inspiring corporate mantras of our generation may have come from the brain of a talented ad guy.