When Maddy Dychtwald was in her teens and twenties in the 1980s, she was a working actor, shooting commercials for Skippy peanut butter and Dupont paint. It was clear that women, especially in her industry at the time, succeeded when they exuded youthfulness and met unrealistic beauty standards. The rhetoric that women hit their prime at a certain age dissuaded Dychtwald from thinking positively about getting older and the longevity of her career.

“You hit 30, 35 at the latest, and if you hadn’t made it big, you just weren’t going to,” Dychtwald tells Fortune . Fast forward 50 years, Dychtwald is now the author of a book called Ageless Aging: A Woman’s Guide to Increasing Healthspan, Brainspain, and Lifespan. She and her husband Ken Dychtwald, cofounders of the decades-old research and education platform, Age Wave , are at the forefront of the age-inclusivity movement.

Their work has profoundly shifted Dychtwald’s perspective on embracing aging, and she takes pride in proving her younger self wrong. Reframing aging makes life more rewarding and plays a massive role in how well people age physically and mentally . For millennia, women have lived longer than men and have a unique opportunity to maximize their “longevity bonus,” Dychtwald, now 74, tells Fortune .

In Ageless Aging , she outlines how women can take advantage of a long life. “Science tells us that women have really won that longevity lottery,” she says. “Aging is an opportunity to reinvent you.