Mark Harmon has been in the business for a long time, after playing bit parts in the 70s until seeing his popularity peak with "NCIS" season 13, which is one of the longest running US shows that also resonated with the worldwide audience.

And the 64-year-old actor has gained a perspective about what that all means, and how he survived Hollywood all these years.

"To be around a while, [you have] a perspective so much time later that maybe you didn't have then. But longevity in the business can be relatively rare," he told People.

Perhaps it's apropos that People gave Mark Harmon major props in 1986 when it named the actor "Sexiest Man Alive."

"I'd done an interview with PEOPLE about leaving St. Elsewhere and I went up to play basketball and both backboards on either side of the court were plastered with the [Sexiest Man Alive] cover," he said. "So that's how I found out."

Although some actors might find that flattering, "NCIS" season 13 cast Mark Harmon took it all in stride.

"There are people who take it certainly much more seriously than I do," he said.

"NCIS" season 13 cast Mark Harmon has been keeping a low-profile although he had some highlights of heroism on his personal life, much like his onscreen character Leroy Jethro Gibbs.

For instance, as a starting quarterback for the UCLA Bruins in 1972, he led the team to an upset of heralded Nebraska Cornhuskers, which was the two-time defending national champion that time, on the score of 20-17.

Outside of the field and in real life, Mark Harmon saved two teens inside a burning car just outside of his home in Brentwood. As the two boys were trapped, he grabbed a sledgehammer from his garage to break the window and pull the teens out of the vehicle.

Perhaps his greatest achievemen was avoiding divorce as he's still married to Pam Dawber since 1987.

Watch Mark Harmon play Leroy Jethro Gibbs on "NCIS" season 13.