“My threshold for existing is pretty low,” Elon Musk explained. (David Paul Morris/Bloomberg News)

When you put two individuals as unique and intelligent as Neil deGrasse Tyson and Elon Musk together, the combination is bound to be memorable. I wrote earlier Tuesday morning about how they discussed artificial intelligence turning humans into its pets.

There was another memorable exchange in their interview, when Tyson pressed Musk about his unusual ambitions as a college student. Musk famously began thinking about humanity’s greatest challenges at a young age. He identified areas such as renewable energy and space exploration, efforts he now leads at Tesla, SpaceX and SolarCity.

But before all that, Musk looked for proof that he would be okay if the grand endeavors failed, and he had almost nothing.

“In America it’s pretty easy to keep yourself alive,” Musk explained. “So my threshold for existing is pretty low. I figure I could be in some dingy apartment with my computer and be okay and not starve.”

So he bought food in bulk at a supermarket to scrape by.

“You get really tired of hot dogs and oranges after awhile,” he said. “And of course pasta and a green pepper and a big thing of sauce. And that can go pretty far, too.

“So it’s like, ‘Oh, okay, if I can live for a dollar a day then at least from a food cost standpoint, well it’s pretty easy to earn like $30 in a month anyway, so I’ll probably be okay.’ “

This isn’t the only example of a young Musk roughing it. When he started his first company, Zip2, he and his brother slept in their office instead of renting an apartment. They showered at the YMCA.

“We were so hard up, we had just one computer so the Web site was up during the day and I was coding at night,” Musk recalled during a commencement speech at USC. “Seven days a week, all the time.”

Related: Musk’s cousin compares him to Neo from the Matrix

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