Image caption Aaron Levie dropped out of university to work on his business

As a man who loves tinned spaghetti hoops, drives a six-year-old car, and holds meetings over a burger at McDonald's, it is fair to say that Aaron Levie is not your average multimillionaire.

He lives in a modest apartment, doesn't take holidays and, at the age of 27, says his biggest luxury is his iPhone.

Yet a multimillionaire Levie most definitely is, with an estimated worth of $100m (£64m).

The boss of fast-growing US cloud storage business Box, Levie is too focused on work to be bothered about luxuries. He doesn't leave the office until the early hours of the morning at least six days a week.

"I work so many hours because I love what I do. I'm incredibly stimulated and excited about the business," says Levie.

"But at the same time, I realise that you do have to a certain level of discipline and determination to succeed in life - you have to work hard and make lifestyle sacrifices. That applies to everyone."

Blue-chip customers

Based in Los Altos, California, in the heart of Silicon Valley, Box provides companies and consumers with remote electronic-data storage, also known as cloud storage.

To begin with I'd pay myself just $500 a month salary and live off instant noodles and Spaghettios

In simple terms, instead of buying a hard drive or server, customers rent space on one of Box's, which they access via their computer or smartphone.

The company is used by 460 businesses on the Fortune 500 list of the largest US firms by revenues - everyone from consumer goods giant Procter and Gamble to advertising company Clear Channel.

Box's revenues last year totalled $70m, up 160% from 2011. And it is worth an estimated $1bn after securing hundreds of millions of dollars of venture capital investment.

This is not too shabby for a company that was founded only in 2005 after Levie, a Seattle native, dropped out of university in Los Angeles to set up the business with his childhood friend Dylan Smith.

"When we started Box in college, it was all about discovering a much better way for people to store data. It was a very exciting time," says Levie, who got into computer programming as a teenager.

Image caption Box's headquarters are very much in the fashionable style you would expect from a Silicon Valley start-up

But as in most start-ups, funds were tight to begin with. Levie says he was initially as cash-strapped as he had been as a student.

"We were making very little money to begin with. I'd pay myself just $500 a month salary [£330] and live off instant noodles and Spaghettios.

"And for the first two-and-a-half years I slept on a mattress in the office. It was like living on a submarine - I'd roll out of bed and start work.

"I'd go more than two days without ever leaving the building."

Fancy restaurant

Fast forward eight years, and both Box and Levie's finances have obviously been transformed.

I think I'm the kind of person who would be very difficult to employ - I'm pretty annoying but driven

Yet while most people in their 20s would probably consider spending extravagantly if they found themselves a multimillionaire, Levie says that doesn't interest him.

"I'm certainly not into money and prestige. For me there is simply nothing more exciting than people involved in the creation of great products. That is what drives me.

"I don't live on the office floor any more - now I have an apartment six minutes' drive away - but there is certainly no mansion up in the hills.

"And I still really like Spaghettios - I'd be happy to eat them all the time. My taste buds really haven't developed much from there.

"The only time I'm in a fancy restaurant is if a client wants that, but we recently concluded a deal while eating at McDonald's."

Many rejections

Back when Box launched back in 2005, there weren't many people who had heard of cloud storage, so securing financial backing for the company was initially a challenge, despite all Levie's hard work.

Image caption Aaron Levie has no plans to sell up

"You have to remember that the computer industry was a very different place back in 2005. This was [five years] before the iPad for example.

"So we certainly had many, many rejections from potential backers. We knew the potential we had, but it certainly wasn't that obvious for potential backers.

"But we were confident, so we just wrote to potential investors. Because we were so confident in Box we had a high tolerance to people saying 'no'. It really didn't dampen our spirits."

One of Box's biggest breaks was sending an unsolicited letter to Mark Cuban, the Texan technology investor who sold internet radio company Broadcast.com to Yahoo in 1999 for $5.7bn.

Mr Cuban's involvement meant other investors were keen to follow and Box began to grow very quickly.

'Excited'

Levie has turned down a number of offers to buy Box.

Image caption Box is continuing to expand overseas

"There are such fundamental changes continuing to take place in the landscape [of the computer industry] that Box has tremendous opportunities going forward. [To sell up] would really compromise on our opportunity," he says.

Now leading Box's international expansion, Levie also says he doesn't think he could ever work for someone else.

"I think I'm the kind of person who would be very difficult to employ - I'm pretty annoying, but driven."