Mark Harmon was exhausted

Mark Harmon was the main face of the “NCIS” franchise for a long time, and is still the actor most associated with the show despite his departure. Harmon played Leroy Jethro Gibbs not only from the very first episode of the flagship “NCIS” series, but even back in the “JAG” days — he debuted in that show’s two-part backdoor pilot for “NCIS” back in 2003. The actor had been a mainstay in film and television since the 1970s, and he may well go on to other things now that he’s said his farewells to “NCIS,” but it’s hard to imagine he’ll ever top what he did as Gibbs.

Harmon’s time as a series regular on “NCIS” ended after the Season 18 finale. He appeared in a few episodes of Season 19 before making his final bow (he technically appeared in Season 21’s “The Stories We Leave Behind,” but just in old clips). So why did Harmon part with the character he had been playing for nearly two decades? In an appearance on “The Kelly Clarkson Show,” the actor explained that he was simply exhausted. He said that he took the job because he thought it would give him more time with his family, but soon found that it was even more taxing than making movies, with “NCIS” sometimes requiring more than 20 hours a day of filming.