What would you ask Jimmy Carter?

I made Jimmy Carter smile.

Which at first doesn’t sound like much of an accomplishment. The man was famous for his smile. It embodied him. That and peanut farming. A peanut with a big toothy grin was enough to symbolize Carter on campaign pins: No name necessary.

But I was meeting Carter at a bad moment — eight years out of office after being crushed by Ronald Reagan, in the middle of what had to be a long day of back-to-back press interviews.

Promoting a book he’d written with Rosalynn, “Everything to Gain: Making the Most of the Rest of Your Life.” He was sour, grumpy, talking over his wife when she tried to speak. I remember thinking, “I don’t care if you were the president, you should let her get a few words in.”

Though Carter really has made the most of the rest of his life. There certainly was enough of it. He was in the Oval Office for four years; he was out of it for 42. Recently, Carter entered hospice care at his longtime home in Plains, Georgia.

Nor was his single term as bad as remembered. Carter’s eventual subsequent slide into malaise makes it easy for Americans to forget what a breath of fresh air he had been in the mid-1970s, after the Greek tragedy of Richard Nixon and the bumbling buffoonery of Gerald Ford.

Carter was smart — a scientist. I campaigned for him, signing up for the “Carter Impact Team.” The Carter White House sent me Christmas cards the four years he was in office. He led by example in office, and his Camp David accords came closer to creating peace in the Middle East than anyone has since.

All that went wrong by 1979. Between the Iranian hostage crisis, the energy crisis, the botched rescue. For me, voting for Reagan was out of the question — I thought the man was Satan, based on his record as governor of California, shrugging off the death of a student protester, shotgunned by a cop, with, “Once the dogs of war have been unleashed you must expect things will happen.”

Reagan received 489 electoral votes to Carter’s 49. Third party candidate John Anderson — I threw away my first presidential ballot on him — took 6.6% of the popular vote, meaning if myself and every single naif who voted for Anderson instead had voted for Carter, Reagan still would have beaten him handily.

Carter became the lone president more distinguished out of office than in. His example of giving his time, building homes for the underprivileged, lending his name to international causes. His 2007 book, “Palestine Peace Not Apartheid,” caused a stir among Jews — some branded him an antisemite. One passage seemed to justify Palestinian terror, but he claimed it was a typo, and the wording was changed in subsequent editions.

Carter was merely ahead of the curve. Now half of college sophomores feel the same way, and attempting to achieve peace in the Middle East by proclaiming blanket sympathy for the Palestinians while shaking your fist at the Israelis is a core practice of liberal orthodoxy.

Our half-hour interview ran by quickly. Carter was having his portrait taken for the magazine. I was still there, and figured I’d better say something. “I always thought you were driven insane by the hostage crisis,” did not seem appropriate.

Suddenly, I remembered the great New Yorker writer John McPhee had canoed through Atlanta on the Chattahoochee River with Carter when he was governor, for a profile on two colorful Georgia conservationists.

”You went canoeing with John McPhee!” I blurted out. “What’s he like?”

Carter broke into his big, famous smile.”Yes, that’s riiiight!” he said, beaming, either because it was a happy memory, or he was amused at the awestruck tone of the question. “How did you know that?”

Not a big secret. McPhee ends “Travels in Georgia” with Carter.

“There was a touch of melancholy in his face that disappeared, as it did frequently, when he grinned,” noted McPhee.

After they were done on the river, Carter invited them all to the governor’s mansion for lunch. Still in their muddy canoeing clothes, they ate grilled cheese sandwiches under the crystal chandeliers, then all played a little basketball — Carter had played on the Plains High School team — and talked about saving the river they had just traveled.

That’s a nice image to bid farewell to Jimmy Carter, at 98 America’s oldest president ever. A man who paddled his own canoe.