Author Simon Sinek once tweeted, “Working hard for something we don’t love is stress, but working hard for something we love is passion.”

Working hard for something you love isn’t just passion; it’s an elixir of life. Meet Agnes Zhelesnik. She turned 102 years old on January 12 and to this day she’s still doing what she loves to do: teaching.

The 102-year old educator — fondly called “Granny” by the students and teachers in school — began teaching more than 20 years ago at The Sundance School, an art-infused Pre-K through Grade 5 private school in North Plainfield, New Jersey.

“It’s an inspiration for everyone that she’s teaching here,” Sundance School head W.J. O’Reilly told ABC News. O’Reilly adds, “Everyday she’s very, very positive, very motivated. She’s always very much focused on the happiness of the children. When asked her secret, she says she loves what she does and she loves taking care of the children and that’s her formula for happiness and success.”

Back in the ’90s, her daughter Agnes Arakelian (who has been teaching art and science at the same school for 30 years) asked her if she wanted to help out in the cafeteria. And when the cooking class was in need of a teacher, Agnes said she can remember being very excited.

The74Million.org, a non-profit education news website, interviewed the 102-year-old educator in a video they titled “America’s Oldest and Most Adorable Teacher Turns 102” in honor of her birthday.

Steven Snyder, editorial director of The74Million.org, says they profile inspiring teachers, educators, and schools everyday, but “Granny’s story is in a clads all its own.”

“All you have to do is see the way the kids respond to her passion, devotion, and commitment,” Snyder told ABC News. “She lights up the classroom.”

In the video she talks about her joy for teaching young children. “I know that they love me,” she said in the video.

The secret behind her long life? “Just be happy with what you’re doing. You have to like what you’re doing,” she says. “My favorite part of teaching is taking care of the children… This is happiness for me.”

Confucius said that if you love what you do, you’ll never have to work a day. If there is truth in that then at 102 years old “Granny” hasn’t been working a day in her life.

Watch CBS News‘ feature on this 102-year-old teacher below.

[Featured image is a screenshot from The74Million’s YouTube Channel. Subscribe to their channel here]