The Georgia town known first and foremost as the home of Jimmy Carter had steeled itself time and again for an existence without him. First, there was his cancer diagnosis in 2015, and then the fall that broke a hip, and the disclosure almost two years ago that he had entered hospice care.

But sure enough, every time, he held on.

And so, Plains, a speck of a community tied to the 39th president for the better part of a century, awoke on Monday to a reality that, strangely enough, seemed almost as inconceivable as it was inevitable. Mr. Carter, 100, was gone. He died on Sunday at his home, the modest ranch house hidden behind the security fencing and guard stations in the center of town.

“Honestly, it doesn’t seem real,” said Philip Kurland, the owner of the Plains Trading Post, an overstuffed emporium of political memorabilia in the strip of business that makes up downtown. “It was inevitable, but there’s still sadness. There’s also a feeling of: Let’s celebrate a life well lived.”

In a serendipitous twist, Mr. Kurland said, he made the purple button that he was wearing to memorialize Mr. Carter just last week. “I can’t tell you why,” he said. Perhaps, it was a premonition, he added. It was also a reflection of how the 500 or so residents of Plains went about life for years knowing this moment would come, sooner or later.

The red, white and blue bows that replaced the town’s holiday decorations on Monday were made months ago. “It’s been something the town has been preparing for,” said Kelly Kight, who owns a floral shop.