Carlos Slim makes his billions from a wide range of investments
He doesn't bother with private jets, shuns flashy offices, and for most of the 1990s made do with a plastic watch.
And while he does have a laptop, he is adamant that he does not use it, saying: "I'm a paper man, not electronic."
Not the kind of attributes you might expect from someone who has now been named the richest man in the world by Forbes magazine.
Mexican tycoon Carlos Slim is now worth $53.5bn (£35.8bn). That puts him above Bill Gates and Warren Buffet, but unlike his US rivals, he remains relatively unknown outside of his native Latin America.
There, he controls more than 200 companies. These range from telecoms, where he first made his fortune, to infrastructure, banking and retail.
In order to maintain his influence over his expanding empire, his sons and sons-in-law have been put in charge of many businesses.
One of the most significant in Mr Slim's empire is America Movil, Latin America's largest mobile phone company, which operates in 11 countries and serves more than 150 million customers.
His telecoms interests also extend to Telmex - the company he fought to take control of in 1990 when it was nationalised. It now operates around 90% of Mexico's telephone lines.
Mr Slim, whose heavy-set figure belies his name, also owns the Inbursa financial group and the Grupo Carso industrial conglomerate, whose interests range from retail stores to restaurants.
Meanwhile, the infrastructure firm he owns, Ideal, is working on a project to develop a shopping centre, schools and a hospital in Mexico City.
The baseball-mad engineering graduate made enough money from working in property early in his career to invest in the stock market.
By the age of 26, he was worth $40m, but it was during the Latin American economic crisis of the early 1980s that Mr Slim made a name for himself as a man who could make money in a recession.
He was able to buy a number of struggling companies at very low prices before transforming their fortunes.
Like Mr Buffett, Mr Slim has done some canny deals in the stock market - not least, buying shares in Apple when they were $17 each. They are now worth well over $200.
The son of Lebanese immigrants, Mr Slim is known for his philanthropy - though not on the scale of Mr Gates or Mr Buffett.
Most recently, he linked up with former US President Bill Clinton and Canadian mining figure Frank Giustra to launch an anti-poverty campaign in Latin America, and in March pledged $6bn for his three charitable foundations.
In Mexico where, according to World Bank data, about 50% of people are living in poverty, many feel that he has not donated enough, especially given how ubiquitous his companies are in day-to-day life.
However his supporters say that some of that criticism is unfair, not least because of his relatively recent elevation to the ranks of the mega-rich.
And Mr Slim, has said he is not convinced that philanthropy is the best way to help people.
"(Bill) Gates has to study how he can (fight poverty) in the same way that Microsoft...succeeded in business, because charity has not solved the problem," he told USA today.
"It's based on my conviction that poverty is not fought with donations, charity or even public spending, but that you fight it with health, education and jobs."
Still working, the tycoon has indicated he has no desire to retire from business to concentrate more on charitable work, as Mr Gates has done.
As he said in a recent interview: "Wealth is like an orchard. You have to share the fruit, not the trees."
If you have yet to hear of Carlos Slim, that may be about to change.
In recent years the tycoon has sought to expand his businesses abroad, including investments in 2008 in the New York Times newspaper and in the struggling bank Citigroup.
In the UK he has been linked with investments in company behind the Independent and Independent on Sunday newspapers.
Analysts suggest he is trying to replicate his Latin American success on a global scale. That remains to be seen, but his rise to the number one spot on the world rich list shows that a global economic downturn is unlikely to slow his progress.