History tells us that when British surrendered to George Washington’s army and its French allies at Yorktown in 1781, the British army band played the tune “The World Turn’d Upside Down” as the lobsterbacks came forward, one at a time, to throw down their muskets.

It was over. What started out as a laugher of a ragtag rebellion against what was the 18th century’s superpower had turned into an unbelievable defeat. Records show Lord Cornwallis did not attend the formal surrender, saying he was ill. I bet he was.

Things don’t always turn out as we expect, and the energy business certainly is an example of that. The oil and gas business has had a profound turnabout in the last decade, thanks to the shale gale, and the world is trying to figure out the implications.

Look at Brazil. As the fourth quarter began, the nation formally began to reverse its decision, implemented one decade ago, to set aside choice exploration blocks solely for state-owned Petrobras to develop, locking out private E&P players. Crude oil prices were zooming upward at the time and the prospect of Petrobras becoming another Saudi Aramco was breathtaking. At the time, then-President Luiz Inacio Lula da Silva said the potential blessing of great oil wealth was so great that God must be Brazilian.

But prices tanked and Brazil’s notoriously inefficient and corrupt bureaucracy worsened the situation, so the nation has endured a long, painful recession. A recent Wall Street Journal article placed the potential loss to Brazil’s economy at $100 billion or more.

Brazil was not alone in making energy assumptions. I’ve recounted on these pages about attending an investor conference in Boston in 2005 that included an economist’s keynote speech on Hubbert’s Peak. The oil business was on the downhill side of its history, he said. It was over.

But North America’s unexpected development of the shale plays in the last 10 years changed all that and now the U.S.—rather than being an oil and gas pauper frantically importing oil and gas—has turned into a powerful exporter that will play a growing role in supplying the world’s energy needs. The energy world turn’d upside down.

So what does that mean for the future? What does it mean for the midstream? No one at Yorktown could have foreseen the French Revolution, Spain’s colonial wars in the 19th century or the emergence of the U.S. as a world power that would supersede mighty Britain. But I’m sure those British troops thought about the future on the long voyage home.

Likewise, it may be a good time to stop and consider what the shales mean for the U.S, both good and bad. Good: The U.S. for the first time in many years serves as master of its own energy destiny. Bad: The swelling supply of oil and gas has tanked commodity prices.

A new book, “Windfall,” by Meghan O’Sullivan, who is the Jeane Kirkpatrick Professor of the Practice of International Affairs at Harvard University’s Kennedy School of Government, takes a serious look at what lies ahead. Previously, she was a special adviser to President George W. Bush. Amazon’s review heralds it as “the boldest profile of the world’s energy resources since Daniel Yergin’s ‘The Quest.’” Yergin himself wrote a glowing review.

She discusses how development of the unconventional plays began and the impact it has had—and will have—on the U.S. and world affairs.

“The frequency with which conventional wisdoms and established understandings were proven wrong should spur us to look for new lenses through which to comprehend the world,” O’Sullivan writes in the book’s preface.

It’s a fascinating read and I’m still working my way through its 459 pages as I write this. But I can recommend it. The assumptions we make about events and their outcomes are not always correct.

Separately, Hart Energy’s DUG Eagle Ford conference was postponed as Hurricane Harvey moved ashore. We rescheduled it for Nov. 15-17 in San Antonio and I hope you will be able to join me there for a great program.

Paul Hart can be reached at pdhart@hartenergy.com or 713-260-6427.