George Clooney: Before He Was Famous

March 2, 2010— -- From a Special Forces soldier in 1999's "Three Kings," an adventurous sea captain in "The Perfect Storm," a suave con artist Danny Ocean in "Oceans 11," to CIA agent in the political thriller "Syriana," he's transformed himself into countless leading roles.

"I was just as stunned as anybody watching it, to see how he did that," father Nick Clooney said. "He undertakes another character and I said, where'd he get that?"

George Clooney is nominated for best actor for his role as corporate hatchet-man Ryan Bingham in "Up in the Air." It's the star's fifth Academy Award nomination. He won best supporting actor in 2005 for "Syriana."

But before he became one of Hollywood's biggest stars, the Oscar-winning actor was another nerdy-looking kid in glasses. People magazine's two-time choice for "Sexiest Man Alive" went through an awkward stage in middle school like everyone else.

"George and his glasses, an experiment that did not work out," his dad joked.

Watch "Before They Were Famous," on a special edition of "20/20" tonight at 10 p.m. ET

Nick Clooney took "20/20" on an exclusive tour of the family house in Augusta, Ky., that his mega-famous son calls home.

CLICK HERE to see never-before-seen photos of George Clooney from his early years

Clooney grew up in Augusta with parents Nina and Nick Clooney and older sister Ada. From a young age, his father could sense that his goofy, outgoing son would become a performer.

"I was sure that he would in one way or another be in a public profession because he just had that knack," he said. "He could contact people and he could make them laugh ...and he was just very interested in performing."

Clooney, an impressionable son, often visited the TV station in Lexington, Ky., where his dad worked as a newscaster and talk-show host, and picked up the lingo without a hitch.

"When George was two, three years old, he got laryngitis. Scared him to death. He came running to his mother, saying, 'Mom, mom, I'm having audio difficulties,'" Nick Clooney said.

Clooney: Social Activist From the Start

His father's job as a newsman instilled an interest in current events and social activism in the boy, which he has carried into adulthood.

"We would talk around the dinner table or the breakfast table or particularly on the weekends when we had more time to spend together. We would talk about whatever was going on in the world," Nick Clooney said. "We would talk about the history of our communities and what were the problems and how they might be solved."

Clooney has used his star power to bring awareness to international crises, including the conflict in Darfur, and last month, organizing a "Hope for Haiti" telethon to help victims of the Haiti earthquake. In 2008, he became a United Nations Messenger of Peace.

Growing Up Clooney

Clooney was an outgoing, charismatic, and optimistic teen, his dad said.

At 13, he developed Bell's palsy, a temporary form of facial paralysis caused by damage to the cranial nerve. For several months, half of his face was paralyzed.

"It certainly affected him at the time," Nick Clooney said. "But even there, George would find ways with humor to make it work for him. He would make fun of himself. He always did that. He tried to make fun of himself before others made fun of him, no matter what the disability might be. Whether it was ... a mistake he had made, or some faux pax he had committed, or whether it was Bell's palsy."

In high school, Clooney was popular and very athletic. He played basketball and at one time aspired to be a major league baseball player, even trying out for the Cincinnati Reds in 1977.

But this jock was also somewhat of a nerd who was president of the high school science club.

CLICK HERE to see never-before-seen photos of George Clooney from his early years

After high school, Clooney went to Northern Kentucky University, but dropped out to pursue acting.

"As soon as he finally decided at age 20 or 19, I guess, that film acting is what he wanted to do, then he was just like a dog with a bone. He just stayed with that with absolute clarity from then on. And has never backed off," Nick Clooney said.

Clooney saved up, selling lemonade to earn money to go out to Hollywood. When he finally moved, he crashed on the couch of his aunt, famous singer Rosemary Clooney.

"He was not beneath being her chauffeur when she needed someone to drive the car when she was on tour," said Oscar expert and film historian Tom O'Neill. "He was not beneath sleeping in the closet at a friend's apartment for a year."

Father to Son: 'Don't Be an Actor'

Nick Clooney said he pleaded with his son to pursue anything but acting.

"I said to him, 'George, please... there are 50,000 broadcasters making a living right now. There are 3,000 actors making a living. For heaven's sake, not acting. Don't be an actor,'" Nick Clooney recalled. "And the moral of the story is always listen to your father."

At first, the jobs were few and far between. He shot eight TV pilots that failed to make it to air. In 1984 he was cast in his first recurring television role in a CBS sitcom ironically named "ER," which fizzled.

The big screen would be no kinder. Moviegoers avoided 1986's "Combat Academy," 1987's "Return to Horror High," and 1988's "Return of the Killer Tomatoes."

At that point in his career, he told his mother Nina, he could only get roles in movies with "Return" in the title.

Clooney trudged forward and landed another television role as carpenter George Burnett in NBC's sitcom "The Facts of Life" in 1985.

For the all-female cast, Clooney was easy on the eyes. Lisa Whelchel, who played the bubbly, "Daddy's Girl" Blair Warner on the show, recalled how hormones spiked when Clooney joined the ensemble.

"And then suddenly this man, who was just testosterone with a capital T, walks into the room and changes the entire dynamic," she said. "Somehow the estrogen level went even further up and at the same time we all just turned into little girls again."

Clooney Was 'Best Unknown Actor in Hollywood'

Jumping from stints on "Facts of Life," to "Roseanne" and "Sisters," Clooney called himself "the best known unknown actor in Hollywood."

"He had regular or recurring roles on a lot of television programs. And he was being well paid and ... he said, 'Pop, I've got the best of all worlds. ..I am the best known unknown actor out here. I don't have to put up with the nonsense. I don't have to be worried about the paparazzi or any of that kind of problem. All I have to worry about is being a working actor, doing my work,'" Nick Clooney said.

Just as he got comfortable being a relative-unknown in a town of big-wigs, Clooney was tapped to play Dr. Doug Ross on a new NBC medical drama "ER." The primetime hospital serial became a smash-hit and made Clooney into a genuine A-list sex symbol.

Clooney Becomes 'Sexiest Man Alive'

"He was then on the cover of Newsweek magazine and the world turned upside down," his dad recalled.

"George Clooney has proven that he's more than just a matinee star on screen," said O'Neill. "He's worked behind the screen as a writer, as a director, and now he's giving these kind of full bodied emotional performances that show us he's the real deal."

Looking back on his son's early years, Nick Clooney sensed that his son's perseverance would make him a star.

"Most of us, whatever we're doing, we find a plateau. It is comfortable. We sort of stay there, kind of hone it, which George didn't do," he said. "He didn't like to be comfortable. He liked to challenge himself. He wanted to get to the next step. So being funny is good. But being good is even better, and he got better and better at everything and he continues to do that now."

Watch "Before They Were Famous," on a special edition of "20/20" tonight at 10 p.m. ET