Actor Mark Harmon has been entertaining us since the early ’70s, but he knows that there’s one person in his life who helped him get to where he is today: his father, Tom.

“My dad taught me, if it’s not true, don’t worry about it,” the 67-year-old told People in a new interview. His father always instilled in him and his two older sisters — Kristen, who passed away in 2018 at the age of 72 and Kelly, 70 —  that it is all about hard work. “I come from working stock, and I’m proud of that. You have to get up every day and just try hard. That’s what I still wake up willing to do: try my hardest,” Mark added.

Mark Harmon
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The Chicago Hope alum learned from an early age what knocking down obstacles was all about, following in the footsteps of Tom, who was a college football star. “I’m a practice guy, a repetition guy,” Mark said. “You can tell me I can’t do something, but I’m likely to take that as incentive to prove you wrong. I’m a tough guy, I’m a jock, so you can yell at me all day long, and that won’t hurt me — I’m just going to try to get better. In this business, I’ve used that to my advantage.”

Unfortunately, Tom died at age 70 when Mark was just 38 years old, but even years later, he continues to move forward with the wise words his father always shared with him. “Work your ass off, and don’t let the effort show,” he said. “Also: Treat people the same, not based on who they are or what they are. Show them common kindness. Don’t be colored by their fame or profession. I don’t get all excited by people blowing smoke up my ass. You have to stay honest.”

Mark Harmon NCIS
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Even though Mark currently stars on the highest-rated drama on network TV, playing the role of Leroy Gibbs in CBS’ NCIS,  he has not let fame change the person he is, as he continues to strive to be the best at what he does. “This choice, this career, requires you to be all in,” he shared. “Your job is to be prepared for the opportunity — it will come, you just won’t know when.” He continued, “So until then, all you can do is invest in yourself … I’ve always worked hard, I’ve always tried to pay attention to the little things — but here’s the real secret: there are no little things.”

“I’m a lucky guy, but you earn luck,” he added.

NCIS is currently in its 16th season.