It was Olivia and Elizabeth’s father who convinced Procter and Gamble (his sons-in-law) to merge their candle and soap-making operations, citing that they were competing for the same raw materials (namely, animal fat and oil).

The moral of the story here: Always listen to your in-laws. (Or at least try to tolerate them the best you can.)

Hewlett and Packard became friends in 1934 after they had both graduated from Stanford University with degrees in electrical engineering. In 1938, they rented a garage in Palo Alto and started working on their first product: an audio oscillator for testing sound equipment.

Hewlett and Packard both took an employee-centric view of management. And as a result, HP became one of the first U.S. companies to offer flexible work hours, profit-sharing, and several other employee benefits.

Gates was adamant that they split ownership of the business 60/40 (in Gates’ favor), citing that he was still a student while Allen was able to earn a salary. A few years later, Gates fought to tip the ownership scales even more (to 64/36).

Jobs and Wozniak met through a mutual friend. They were exposed to the latest personal computing technologies by way of the Homebrew Computer Club in Silicon Valley

“We never had a fight or an argument,” he told the Milwaukee Business Journal back in 2014. “We were always friends.”

After meeting with Avey several more times and learning more about the project, Wojcicki came to a decision: She wanted in. Avey was happy to have her, and the two worked together in a shared office to get 23andMe off the ground.

Remember: Building a successful company is a marathon, not a sprint.

Fortunately for ice cream fans everywhere, no one would buy Cohen’s pottery, and no medical school would accept Greenfield. So after debating between starting a bagel business or starting an ice cream business, they chose the latter based on the lower start-up costs.

Cohen once said. “Our relationship hasn’t changed at all … Food has always been our binding tie — food and our girth.”