Inventor Erno Rubik thought his cube was so difficult that no one would buy it: now it has sold 500 million

Hungarian inventor Erno Rubik, 79, was born in Budapest in 1944 to a flight engineer father and a poet mother, writes Dan Moore.

After high school he aspired to become a sculptor, before becoming a professor of architecture at the Academy of Applied Art and Design in Budapest.

In 1974, he invented a wooden puzzle with moving parts to help his students understand space, problems and geometric shapes, which became known as the Rubik’s Cube.

It turned out to be a big hit, first with his students, then among Hungarians, before becoming a worldwide phenomenon.

Now in its 50th year, 500 million Rubik’s Cubes have been sold worldwide, making Professor Rubik a multi-millionaire.

Professor Rubik is now retired and lives between Budapest and Spain with his wife Agnes Hegely. The couple has three daughters and a son.

What did your parents teach you about money?

Money wasn’t a common topic of conversation, partly because we hardly talked about it. My childhood was behind the Iron Curtain in 1950s Hungary, so we just learned to make do with what we had. I think that stuck with me because even now I don’t think about money anymore unless I have to go to the bank.

What was your first job?

I was about 15 and teaching math to girls at my former high school. Salaries were controlled by the state, but the wage equivalent of a teacher today would have been around £800 per year. From there I went to university and then to postgraduate study in 1962, where I also taught and was paid about £1,200 in today’s money.

Have you ever struggled to make ends meet?

Not in a way that matters to me, because I don’t admire money. For me, money is a practical way to exchange goods, but I’ve never chased cash or thought about whether I lack it. If you have something to eat, something to wear and time to do what you want to do, that’s enough.

I have never been interested in accumulating money, which is a popular pastime for many people. I’ve seen how hard it is for billionaires to lose $20 billion in a year, which would be like losing a dollar to you. It’s very tragic, I’m sure.

How did the Cube come into existence?

As an engineer, I found the technical challenge of the construction very interesting and initially it took me a month to solve the problem. I didn’t dream of winning the jackpot by inventing a puzzle. I just found it interesting, and other people – my students and others around me – found it fascinating too.

At first I thought the Cube wouldn’t sell because it was too difficult. But I realized that nothing is too difficult for a teacher to teach and for young people to learn.

The Cube is a cheap thing, but intrigues and inspires young people in a good way, which is important.

How did you get it to market?

I got some ideas from my father, who worked as a flight engineer in an aircraft factory, so I applied for some patents. I was also looking for a company to manufacture it, which was not an easy task in Hungary at that time. Three years later, around 1978, it came onto the market. It started selling in Hungary and the first order was, I think, for 5,000.

By 1980, one million had been sold in Hungary. To be clear, I made a little, nothing spectacular, just a small profit.

Was it difficult to expand?

Getting past the Iron Curtain was no easy task, but I eventually succeeded and the Cube was introduced to America. But going to the US was difficult because I was only allowed to buy a maximum of $250 in cash, which wasn’t much to get by while trying to promote the Cube.

Was there a limit to how much you could earn?

Yes, the Hungarian authorities placed restrictions on how much hard currency you could bring into the country.

This wasn’t really a problem as I was able to sell my very nice little Fiat 500 and buy a Volkswagen Golf for hard currency, which was very exciting.

Have you ever been given bullshit money?

I’ve never been sure how many Cubes were manufactured and sold in the US, but I understand it was about three million units in two and a half years. There was a lot of hype, it became a rage in America and much of the developed world. This has made a lot of money, but I’m not a billionaire.

Phenomenon: 500 million Rubik’s Cubes have been sold worldwide

It still sells well – it’s like that old saying – ‘every joke is a novelty to the newborn child’.

What was the best year of your financial life?

Financial success always depends on one’s circumstances, material desires and immediate environment. Receiving a significant dollar amount in state socialist Hungary was indeed exceptional. However, this changed very little throughout my life, as my personal needs have always been quite modest and I have never liked spending money – in fact quite the opposite.

What’s the most expensive thing you’ve ever bought for fun?

A few years ago we decided we wanted to spend more time on the Mediterranean, so I bought a house in Spain. I enjoy the weather and the clear sky there in winter.

What was the best money decision you ever made?

I ask my wife Agnes to take charge. She prevents me from making bad decisions.

Do you have a pension?

Like most countries in Europe, Hungary offers a state pension, so I have been receiving a small pension for over ten years now.

Do you have property?

We live in a four-bedroom, five-storey family home on a hill in Budapest, plus our house in Spain.

What is your number one financial priority?

The highest financial priority for me, as it should be for the governments of the world, is educating young people. I believe that half of a government’s budget should go to education.

• Erno Rubik’s puzzles are available at rubiks.com