Betty White is celebrating another year of life, but if you ask her about her age, she’s quick to remind you of one crucial fact: age doesn’t really matter. The star turned 99 recently, and she’s woring. “You don’t stop once you pass a given age,” she said in an interview back in 1991, “You don’t lose any of your zest for life.”

Now three decades later, and in the face of continued sidelining of older women on-screen, she has continued to have a thriving career—and it’s part of her secret to longevity. “I don’t exactly have a secret,” she said in a magazine interview. In the same breath, though, she said she never plans to retire. White said, “I just love to work, so I’ll keep working until they stop asking.” We think there are a few things she’s done in her life that may be to thank for her longevity:

White’s love of her work, and the sense of purpose it gave her, is probably a major part of Betty’s years of ongoing success. White acknowledges that staying busy has been an important part of her long and prolific life. She encourages others to find their purpose and to run with it. “It’s not difficult to find things you’re interested in,” White told Katie Couric in an interview to celebrate her 95th birthday. “Enjoy your years, indulge your purpose.” If finding your purpose in life is too intimidating at the moment, start small and find some things you love.

In the same interview with Katie Couric, she also suggested taking a broader view of their world and their life: “Don’t focus only on yourself; because that wears out pretty fast.” She’s also all about self-reflection: “You may be able to lie to others—not that I would—but you can never lie to yourself,” she said. In the same vein, the actress also shared that she always tries to focus on “looking at the positive side,” on the joyful moments and happy things.

White is actively committed to supporting many causes, many tied to things she loves, like animals. White has been a trustee of the Greater Los Angeles Zoo Association and even wrote a book titled “Betty & Friends: My Life at the Zoo.” White had also said she wanted to be a forest ranger or a zookeeper before deciding to pursue acting. She’s even been made an honorary forest ranger.

The other thing she focuses on? Being in the present and appreciating what life has given her. “I don’t think about things I may have missed out on,” she stated. In her Couric interview, she also gave advice for dealing with grief, saying she focused on what was happening at the moment. “You don’t need to look ahead, and you try not to look back,” she said. Whatever the secrets are to her long and fruitful life, White’s doing something right, and one thing is for sure: Her work brings joy to many others, and for that, we’re grateful. Happy birthday, Betty!