Most people who love Ireland fell in love with the one that used to be desperately poor, ridiculously friendly and breathtakingly beautiful.

David McWilliams's brilliant, readable The Pope's Children: The Irish Economic Triumph and the Rise of Ireland's new Elite (John Wiley & Sons, $26.99) is about a different Ireland, a modern one, where the poor are now rich, the friendly are too busy to be as friendly, and that green quilt of countryside is dotted with vacation homes of wealthy Dubliners who barely use them because they've also bought property in Bulgaria and they're on holiday in Spain or a shopping weekend in New York or Boston.

Economist McWilliams explains the revolutionary, evolutionary change in the Irish, from the perpetually poor post-colonial pessimists to the unbridled optimists whose ambition and consumerism drove the Celtic Tiger, the most robust economy in the western world for more 10 years.

"One hundred years ago, the perfect image of the Irish was a doodeen-smoking, seaweed-picking, barefooted peasant, smiling in bewilderment for some well-meaning English anthropologist who has just measured the circumference of his cranium," he writes. Today, "a perfect snapshot of the Irish is of a man in an expensive, ill-fitting suit, hands full, driving or maybe carrying a child distractedly, barking orders down a mobile phone on an English-owned network."

It is an unflinching account, paying tribute to the rising tide that lifted all boats and created a bulging middle class, while highlighting some of the less attractive byproducts of prosperity -- young people who abuse alcohol more than their European peers, rampant materialism, mad traffic and long commutes on formerly quiet, bucolic roads.

The Irish, McWilliams says, are fatter, drunker and happier than ever.

"We are Europe's hedonists," he writes, "and the most decadent Irish generation ever."

The book's title refers to the generation of Irish born after Pope John Paul II arrived to a rapturous welcome in 1979. The Irish baby boom peaked exactly nine months after the pope's visit. Ireland, meanwhile, has become a much more secular country, a place where that pope would now be regarded as just another guy from Krakow.

The book, initially published in 2005 in Ireland, was written largely for an Irish audience, and some of the references will be lost on someone without an intimate knowledge of contemporary Ireland.

McWilliams can be too fond of his metaphors, repeating pithy phrases until they become decidedly less pithy.

But this book is indispensable for understanding how Ireland went from being one of the poorest countries to one of the richest in a short time, and how this has changed the question of what it means to be Irish. In a land once known for producing saints and scholars, McWilliams captures the contradiction that is a prosperous, materialist Ireland.

"There was a fundamental shift in our culture that could not be ascribed to money, immigration or politics," he writes. "Old conservative Ireland has become a magnet for pagan New Age travellers and old liberal Ireland is brimming with evangelical Christians."

McWilliams concludes that despite the materialism and hedonism, there has also been a revival in Irish culture, especially the language, which used to be forced on a reluctant populace by the government but is now being embraced by a people who with all their success are perhaps more determined to hold onto something that resides in their soul, not their bank account.