She rented the club and hired a singing coach. That night she raised $7,000. Her friends cheered her moxie. So much so that a few of them told her they were inspired to pursue creative projects of their own.

Bill Burnett, the executive director of the design program at Stanford University and an author of the best seller “Designing Your Life,” said he had seen a growing number of midlife professionals use his book to re-engage their creative side. “Many remember something about themselves when they were feeling creative,” he said. “And it feels good.”

The challenge is to bring the experience into everyday life. Most people won’t leave their jobs (even if they fantasize about it) and take up painting in Provence. There are bills to pay, after all, and rookie oil paintings rarely cover the mortgage. Then, of course, there is ego.

“Fear of failure is big if you’re an expert in your field,” Mr. Burnett said. “They question, ‘Why am I going to do something new that I’m terrible at?’ There is the psyche that says, ‘Don’t do that.’” What people want, Mr. Burnett said, is permission.

In 2016, Elana Frankel left her job as the creative director of One Kings Lane, a luxury furniture and home décor company. She took photographs, but wanted something more. “When I was a kid I absolutely loved painting,” she said. So she bought some acrylics and began to paint, using her photographs as inspiration.

Buying more stuff wouldn’t have satiated her curiosity. “For so many people, when they hit their 40s, probably the most important thing is the inner desire to better themselves,” Ms. Frankel, who is in her 40s, said. “I stopped to focus on my needs. And it does not feel like a selfish pursuit.” Now she paints with her two children.

“It feels like a communal activity,” she said.

Ms. Cameron, 70, said she created her 2016 book as a tool kit for her middle-aged friends. “People are looking for structure,” she said. “People need to have encouragement.”