Michael Weatherly, <i>NCIS</i> Michael Weatherly, NCIS

Michael Weatherly shares plenty of similarities with Tony DiNozzo, the character he has played for eight seasons on NCIS.

Weatherly and DiNozzo are both energetic cut-ups who always seem in search of a punch line. And they both talk a lot. Like, seriously, a lot.

"Energy is the biggest part of my job," Weatherly, 42, tells TVGuide.com. "That sounds weird, but if I'm in a scene, I try to punch it up. And sometimes I really overdo it and they have to cut around me."

Check out photos of Weatherly throughout his career

And of course, Weatherly and DiNozzo are different in many ways."Everyone assumes that I must've played football or was a college athlete," Weatherly says. "I wasn't a jock in school, and by the 10th grade, when I was in boarding school I was carrying water buckets for the girls' hockey team. I was the kid with long hair and glasses and acne trying to learn how to play guitar and piano in the music center. I was not an athlete past the age of 13 or 14 when they start throwing the ball really fast."Weatherly wasn't much of a student, either.Born in New York and raised in tony Fairfield, Conn., Weatherly dropped out of college to pursue an acting career in New York. He was still the kid with long hair and glasses when he made his TV acting debut

on The Cosby Show as one of Theo's college classmates.

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"I believe they cut my lines. I wasn't very good at saying them," Weatherly says. "It threw me into the fire. I had no idea what I was doing. I had done a couple of plays, but I was a clueless boob. Cosby allowed me to have something on my resume that was real and then the producers of Guiding Light let me play a preppy killer just the following month. Suddenly I had two gigs on my résumé that made me look like a real actor, although I was far from it."Those roles eventually led to Weatherly being cast as Cooper Alden on the ABC soap opera Loving in 1992. He played the role for four years, even appearing on the short-lived spin-off, The City. It was on the set of those shows that he met his first wife, Amelia Heinle. The two divorced in 1997 after two years of marriage and the birth of their son, August.Although Weatherly credits Loving with helping to launch his career, he maintains that he still wasn't much of an actor. "During the run of our show, we'd work during the day and I'd go to the bars at night," he says. "Other cast members would do plays at night: Paul Anthony Stewart was doing Cyrano de Bergerac on Broadway. He was a real actor, and I was still doing my impersonation of what I thought an actor should be getting up to."

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After the soap ended, Weatherly moved to Los Angeles, where he did a number of guest spots on TV series. He eventually won a series regular role on Fox's Significant Others with Jennifer Garner, but the show only lasted six episodes. After director Whit Stillman cast Weatherly in The Last Days of Disco opposite Chloë Sevigny, he spent several years pursuing a film career, with notable appearances in Cabin by the Lake and Trigger Happy."The big turn in the late '90s was that I realized I was going to be doing this for a long time," Weatherly says. "I was fairly sure I was going to be an actor for the rest of my life, which I think calmed me down."In 2001, James Cameron cast Weatherly opposite Jessica Alba in Dark Angel. Playing cyberjournalist Logan Cale, Weatherly worked through some of his other insecurities."I thought people thought I was stupid. I always thought I had to try and impress people and be really smart because I was always insecure about not finishing school," Weatherly says. "My father and mother are both very smart people and I always felt I was a little short of the mark. So I would compensate with a character like Logan Cale. He's wearing glasses, he's in a wheelchair, he's a computer genius. He's very far away from who I am, but I really wanted to play roles where I'd be taken seriously."

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But Weatherly says accepting the role as DiNozzo on NCIS in 2003 allowed him to stop worrying. "He's irritating to a lot of people, but he's a lot of fun and he's very genuine and it's a different kind of looseness you find as an actor when you get to play a part like that," Weatherly says.In recent seasons of NCIS, many fans have become obsessed with the romantic tension between Weatherly's character and co-worker Ziva (Cote de Pablo). Weatherly, who married a co-star and was engaged to Alba off-screen while working on Dark Angel, relates to the struggles of office romance. "I remember very strongly the inevitable feeling I had about Jessica when we were doing Dark Angel because it was like I was the Millennium Falcon being sucked into the tractor beam," Weatherly says. "I didn't feel I had any control over that part of my life. I think that the same thing does happen for Tony. ... He does feel Ziva really understands him on this fundamental level that even he doesn't quite understand."After playing the character for eight years, however, Weatherly sees his greatest similarity with the wisecracking NCIS agent: They're both the No. 2 guy. Even on DiNozzo-centric episodes, Weatherly sometimes takes a back seat. For example, on Tuesday's episode (8/7c on CBS), which features the return of DiNozzo Sr. (guest star Robert Wagner), Tony is shocked to learn that his father has been called in to go undercover with Ziva.

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"My son said to me once, 'When are you going to be 'the guy'? You're always the guy next to the girl or the guy next to the guy,'" Weatherly says. "The weird thing about my career at this point, by and large, is I've perfected the No. 2 slot. I've had a No. 2 next to my name on call sheets for so long I'm pretty loosey-goosey about the whole thing."So does Weatherly, who married again in 2009, hope to move up that one extra spot one day? "It would be deeply disingenuous of me to say that I'm not fascinated by that kind of role," he says. "For the time being, I'm really good where we are. My life has changed so much in the last few years, personally. It has become about different things. When I go home, I've got another job, which is to be a husband and to try and connect with my 14-year-old son, who I don't see as much as I'd  like to."I feel very centered and grounded and happy, as corny as all that is," he says. "So when I look forward now, I don't have the anxiety. There's a lot of other stuff going on in the planet than what I want to do in terms of films and television."