Even if you haven't read Don Miguel Ruiz’s first book, The Four Agreements, you know someone who has.

Published in 1997, this classic has sold more than eight million copies in the U.S. and has been translated into 46 languages. Don Miguel has steadily written other books since, including Master of Love, The Toltec Art of Life and Death, and The Three Questions, among others.

At age 68, the Mexican-born, San Diego-based author has just published The Actor: How to Live an Authentic Life, the first in a mystery school series. The second in the series, The Myth, will come out later this year, as will the third. So what exactly is a mystery school?

“Many people say they learn in the school of life, and that’s really what it is,” Don Miguel explains. “It’s life revealing secrets to us.” He’s always been known as a storyteller who uses that form to convey his spiritual wisdom. “Language is how we create ourselves,” he says.

In the play “As You Like It,” William Shakespeare wrote that “All the world’s a stage, and all the men and women merely players. They have their exits and their entrances, and one man in his time plays many parts.” The idea that we create not only our own perception of reality but also our identity is something Don Miguel has long thought about. He first observed people switching from one role to another at his brother’s funeral, when he was only 10, and he could see the people around him being sad one moment, then gossiping with a friend in the next. His belief that we all create our identities also came up in an important conversation with his grandfather when he was 17, when the older man told him that everyone is living in their own bubble, created with the knowledge they have—or think they have.

“When you are an actor, everyone is a critic,” Don Miguel says. “We try to please everyone and then we start acting, and the worst critic of all is ourselves, trying to really accept the way we behave and the way we act.”

“We learn the different rules as we are growing up, we see the expectations that are placed on us, we start to pleasure everyone, and little by little, we lose the authenticity,” says Don Miguel. But there is good news, too. Once we are aware that everyone around us is also an actor, we realize that we get to write our life script. “And if we don’t like the way we are living, we can change that script.”

In his early years, Don Miguel was cast in the role of sibling—he is the youngest of 11 brothers and two sisters. Then he played the role of doctor, becoming a practicing surgeon. But he gave up medicine in 1986, choosing to share the Toltec teachings and philosophies he had been learning from his family. Since then, he’s been dedicated to sharing that wisdom.

“With this series, I want to share whatever I can, with minimum effort for the reader, in a way that anyone can understand.”

Don Miguel recently celebrated a milestone: It has been 10 years since he received a life-changing heart transplant. A heart attack in 2002 had left him with only 16 percent of his heart’s capacity, and he spent nine months in a coma. “I had to learn to walk, to coordinate. I felt it was a race against death, doing as much as I could before I died.” Still weakened, he eventually was put on the list for, and received, the transplant.

While Don Miguel’s health is not perfect, he says, “I am going to live more years hopefully, and keep sharing, and to give, and that is the point of life. I want to keep writing and if people accept it or reject it, that is okay. With this series, I want to share whatever I can, with minimum effort for the reader, in a way that anyone can understand.”

Books, he says, are a kind of magic, because a reader may return to read something six months or a year later and find a completely different meaning. “But the book hasn’t changed; they are the ones who have changed,” he observes. “I really share the same message in all the books, but in different ways. All those life secrets are revealed to us.”

Each of our lives are meaningful and important and unique, Don Miguel reminds us. “Nobody can do the same work you do as you.” In fact: “We play the role of ourselves so well we can get an Academy Award.”