“When I was about 11 years old, we had an American boy stay with us for a week, an exchange student,” she recalled. “And my mother told him, just make your own sandwich like you do in America. Instead of putting one sausage on his bread, he put on five. My mother was too polite to say anything to him, but to me she said in Dutch, ‘We will never eat like that in this house.’”

At school, Ms. Verkoelen learned from friends that the American children in their homes all ate the same way. They were stunned and a little jealous. At the time, it was said in the Netherlands that putting both butter and cheese on your bread was “the devil’s sandwich.” Choose one, went the thinking. You don’t need both.

Building the earth’s biggest sailing yacht and taking apart a city’s beloved landmark? That’s the devil’s all-you-can-eat buffet.

The streak of austerity in Dutch culture can be traced to Calvinism, say residents, the most popular religious branch of Protestantism here for hundreds of years. It emphasizes virtues like self-discipline, frugality and conscientiousness. Polls suggest that most people in the Netherlands today are not churchgoers, but the norms are embedded, as evidenced by Dutch attitudes toward wealth.

“Calvin teaches that you’re given stewardship over your money, that you have a responsibility to take care of it, which means giving lots of it away, being generous to others,” said James Kennedy, a professor of modern Dutch history at Utrecht University. “Work is a divine calling for which you will be held accountable. It’s considered bad for society and bad for your soul if you spend in ostentatious ways.”

There are billionaires in the Netherlands and a huge pay gap between chief executives and employees. Statista, a research firm, reported that for every dollar earned by an average worker, C.E.O.s earned $171. (The figure is $265 in the United States, the widest gap of any country.) The difference is that the rich in the Netherlands don’t flaunt it, just as the powerful don’t highlight their cachet. The Dutch once ran one of the world’s largest empires but there’s a certain pride here that the prime minister of the country rides a bicycle to pay visits to the king — yes, the Netherlands has a royal family, which is also relatively low-key — and locks the bicycle outside the palace.