SWINDON, England — Mr. and Mrs. Average are said to live in this southwestern English town better known as a political bellwether than for any charm. Its 54.7 percent vote for Brexit in 2016 was one of the first results announced, an early indicator of upheaval. Now, with less than a month until the March 29 deadline for Britain to leave the European Union, it’s again aligned with most of the country, this time in its cluelessness as to what is about to happen.

To paraphrase Churchill, much invoked by Brexiteers as a symbol of the rule-Britannia greatness they believe will return once Britain is freed from its European shackles: Never was so little known by so many about so much.

Britain is in a funk. “Just get this over with,” is a plea I heard often from Brexit-battered Brits, as if they were waiting to have a limb amputated. After nearly three years, they’re done. All the oxygen has been sucked from the room by the Conservative Prime Minister Theresa May’s floundering attempt to end the country’s 46-year membership in the European Union.

It’s not easy to make an egg from an omelet, as Pascal Lamy, the former head of the World Trade Organization, has observed. I grew up in a Britain where “the Continent,” a faintly distasteful geographical mass associated with rabies and garlic, was far away. The E.U. changed that. Now, through finance, trade, law, values and culture, Britain is mixed into a borderless market of 28 nations and more than a half-billion people that has brought peace, stability and an unprecedented, if uneven, prosperity to Europe. Britain’s decision to break from that is a curious act of self-harm, linked, like the election of Donald Trump, to the desperation of our times.