NCIS Star Mark Harmon's Secret to Success: "You Earn Luck"

Mark Harmon has been in the public eye for 40 years and has learned the secrets to his success. He credits his father, who was one of the most important people in his life, with teaching him these skills.

The NCIS star tells PEOPLE in this week's cover story, "My dad taught me not to worry about things that aren't true."

"I'm proud to say that I come from working stock." Harmon, 67, says, "You have to get up every day and just try hard." "That's what I still want to do every morning: give it my all."

Harmon grew up in Burbank, California, with his parents, Tom Harmon, a former football and TV star, and Elyse Knox, his wife. He also had two older sisters, Kristin, who died at the age of 72, and Kelly, who lives in Los Angeles and is 70 years old.

Tom was a great college player who played for two years in the NFL, and Harmon did the same thing, starting as a quarterback for UCLA.

"I like to practice and do things over and over again," he says. The more you tell me I can't do something, the more likely it is that I'll do it anyway. You can yell at me all day because I'm a tough guy and a jock. It won't hurt me; I'll just try to get better. That has helped me in this business—thanks.

While Harmon was only 38 years old, his father died at the age of 70. However, the experienced actor still follows the useful advice that Tom gave him.

"Do your best, but don't let it show," he says. Also, don't treat people differently because of who they are or what they are. Please be kind to them. Don't judge them based on their fame or job. I'm not excited when people blow smoke up my behind. You need to be honest.

Harmon has been famous for a long time, but his part as Leroy Jethro Gibbs on CBS's "NCIS" has made him famous. The show has been the network's highest-rated drama for 16 years. Harmon has also won a Golden Globe and an Emmy.

People named Harmon their second-ever Sexiest Man Alive in 1986. Harmon is married to actress Pam Dawber and they have two boys together, Sean, 30, and Ty, 26.

But fame doesn't bother the star who is known for being very private.

Instead, it has made the father of two very thankful and pushed him to get better at his job every day.

"You have to be all in for this choice, this career." "Your job is to be ready to the chance; it will come, you just won't know when," he says.

The star says, "Until then, all you can do is put money into yourself." "I've always worked hard and tried to notice the little things, but there aren't any little things."

Some people are born lucky and starry-eyed, but Harmon thinks he needed more to have a long-lasting job in Hollywood.

Harmon said, "I've always thought that you make your own luck." "You shouldn't just sit around and wait for chances to come your way." It's about working hard, getting better at what you do, and being ready when the chances come up.