Years of auditioning: "At 33, I was still a nobody," reveals George Clooney

Clooney's early acting career was an uphill climb. It's rather surprising that an actor of his caliber, who is now one of the most sought-after Hollywood stars of the 21st century, faced so long a struggle to establish himself in the film industry. "At 33, I was still a nobody in Hollywood. I attended auditions for over a decade, most of which ended at the initial stages," George Clooney revealed in an interview with Variety.

Clooney's first acting roles came about 40 years ago. In 1983, he appeared in two productions — "Grizzly II: Revenge" and the TV series "E/R". The former was a lackluster thriller that was relegated to the video market, while the latter was a respectable comedy that anticipated his future TV blockbuster "ER".

Clooney's breakthrough moment arrived in 1994, when the 33-year-old actor landed a five-year contract to appear in the TV series "ER." His portrayal of Doctor Doug Ross rocketed him to fame. Clooney could have continued riding the wave of that TV success. But, instead, he made a bold decision to pursue a film career in Hollywood.

"Most people questioned, 'What are you doing? A TV actor won't make it in Hollywood.' Truly, it was a chancy move. I loved 'ER', and the people I worked with. But I understood that if I stayed with the series any longer, I would always be associated with the role of Doug Ross," reminisces Clooney.

George Clooney left "ER" in 1999, during its fifth season (although he later made a few guest appearances). By the time "ER" wrapped up after 15 seasons, Clooney had already earned an Oscar for Best Supporting Actor in "Syriana" (2005), and received three Academy Award nominations — for directing and screenplay for "Good Night and Good Luck" (2005) and for the lead role in "Michael Clayton" (2007) — and starred in various box office hits.