Kathy Denton, 64, said she felt “bolder” now, in part because she no longer experiences the pressure she once did to settle down. She has been able to find fun with some of the men she has met through dating sites, even if none have been a long-term match. One “delightful man” cooked her “the best soups and breakfasts”; another swept her off to his condo in Florida and showed her “how to have fun again.”

Ms. Denton would like to fall in love again, but she has also “fallen in love” with herself, she said, and realizes that she is the only company she needs. She goes to the beach, spends time with friends and plans to enroll in a stained glass-making class. “If I had to spend the rest of my life alone, I’d be fine with it now,” said Ms. Denton, who lives in Michigan. “I love my life.”

‘We Need a Lot of Patience’

Dating after 60 isn’t all roses. Several people interviewed for this article mentioned how frustrating it is to meet people whose toxic behaviors have calcified over decades.

“We need a lot of patience with each other to undo some of this crap we’ve been through,” said Ms. Denton, who added that she had dated men who turned out to be compulsive liars, or who she suspected had alcohol issues. She has interacted with men who clearly did not bother to read her profile, she said, and others who sent naked photos. Some daters also brought up sexual dysfunction, the shrinking dating pool for older women and the threat of being scammed.

But for Ms. Ha and Mr. Ecker, opening themselves up to each other has brought them both surprising happiness at this stage in their lives. Mr. Ecker had been dating off and on for 10 years before he met Ms. Ha, and was coming out of a particularly difficult stretch when they connected. His mother and his beloved dog had both died, he had ended a three-year relationship and he had lost a chunk of his savings to stock market volatility, just as he was preparing to retire.

Now, he and Ms. Ha are planning the next stage of their lives together, thinking about what they want retirement to look like. They feel lucky to have found one another. “Ever since that first message she sent me,” he said. “I have felt that this thing has been guided and out of our control.”