It’s hard to remember from a modern politician a more poignant l’envoi than David Cameron’s final cry as prime minister, “I was the future once.” It was a reference, we were reminded by the Mirror, to his jibe at the expense of Tony Blair when the two clashed for the first time at prime minister’s questions and Mr. Cameron delighted the Tories by saying of Mr. Blair: “He was the future once.” How, not to put too fine a point on it, time flies.

What makes Mr. Cameron’s exit so poignant is not just the speed with which the future escaped him (he led his country and party but six years). It’s also the nature of his argument against independence for his own country. He sought to portray it as retrograde, a reach for an impossible past. He held out the socialist satrapy in Brussels as a logical future, a modern world, only to discover that his countrymen are more clairvoyant than he is.

Forgive us, but it reminds of the scene in “Back To the Future,” when Marty McFly is playing the guitar as his parents’ high school dance and breaks into an rollicking rendition of “Johnny B. Goode,” prompting one of the backup musicians to call his cousin and, while holding the phone so his cousin can hear McFly on the guitar, shout: “Chuck! Chuck, it’s Marvin. Your cousin, Marvin Berry. You know that new sound you’re looking for? Well, listen to this!”

How sad it was that Mr. Cameron failed to grasp that the future always lies with freedom, the essential atmosphere of creativity. It strikes us as bizarre that the British forsook Boris Johnson for, in Teresa May, a Tory who had sided, even tepidly, against independence for her country. But we’re at least guardedly optimistic that she has included Mr. Johnson in her cabinet as Foreign Secretary. Why she needs a separate secretary of state for exiting the European Union, this is not so clear to us. But at least she has vowed so bluntly to be bound by the Brexit referendum.

We ourselves are not against all of the elements of the European dream, which we covered during the crucial years of the 1980s. And we understand that Britain under George III was not always on the side of American liberty. We also understand, though, the ovular role of the Mother of Parliaments in the spread of democracy and self-government. What an example it sets and what an exciting future it has opened with Brexit.