'Blue Bloods' Star Tom Selleck Reveals the Real Reason He Quit 'Magnum P.I.': 'I Was Tired of It'

While the original Magnum, P.I. could have run much longer than eight seasons, series star Tom Selleck effectively put an end to it after choosing to walk away from one of the most popular television shows at the time. Recently, the famous mustachioed actor revealed why he left Thomas Magnum behind in 1988 — and why he took an extended break from Hollywood during the early 1990s.

"I quit Magnum, not because I didn't like it or I was tired of it," Selleck — who now stars on CBS' Blue Bloods, which ended its 10th season this past spring, told PEOPLE "I was tired of it. And I wanted a three-dimensional life because I didn't have one." The same year Selleck left Magnum behind, he bought a ranch in Venice, California, and has lived there ever since with his wife of 33 years, Jillie.

"My relationships and my ranch keep me sane," Selleck, 75, said of the property, which included a working avocado farm until a recent drought. It is also home to 1,500 native trees. "I do grunt work, and I make the rounds. I like watching things grow. It's a retreat."

Since Magnum ended, Selleck focused on finding a perfect balance between time working and time with his family. Selleck also has two children, Hannah, 31, and Kevin, 54, from his marriage to Jacqueline Ray. "I knew intellectually what it would mean in terms of being a public person, but until you've lived it, there's no way to understand it," Selleck told PEOPLE. "I had a feeling of, 'I don't think I'm cut out for this.'"

Selleck started in Hollywood in 1969, working almost non-stop in films and television shows until Magnum ended. In the mid-1990s, he began working again, with roles on Friends and popular made-for-TV Westerns. In 2005, he made his first Jesse Stone movie, Stone Cold, which made him popular with CBS viewers.

In 2010, he was cast as New York Police Commissioner Frank Reagan, a role he has had ever since. "I'm proud of my work, I still love what I do, and I have my family," Selleck told PEOPLE. "I've been enormously fortunate."

His co-stars also appreciate Selleck's experience. "He's so dedicated to his work that you're not going to come in and tell him these magnificent ideas that you have of how to make his scenes special," Wahlberg said in a PopCulture.com interview earlier this year. "He's already come up with 500 ideas himself a week before you even sit down with him. That's how devoted he is to his work."

Blue Bloods returns Dec. 4 at 8 p.m. ET on CBS. For more on the show, Tom and all your favorite stars and shows, keep it locked to PopCulture.com!