The `James Bond` actor - who resumes his role as the iconic British spy in the next instalment of the franchise, `Skyfall`, next year - is "constantly" unhappy with his work, as he is a perpetual perfectionist.
He said: "I`m definitely not satisfied about my career. I don`t know how you can be; it`s the very nature of things. I`m always trying to figure it out and I`m kind of unsatisfied constantly. I always want to get it right and I don`t know what the answer to it is.
"But I do know that it`s out there and I do know it`s worth looking for."
The 43-year-old star also admitted he finds it "extraordinary" he was cast as Bond at a time when he had done nothing similar in his career and is still unsure how he was successful in the role.
He added to Britain`s GQ magazine: "What`s extraordinary is that at a point in my career when I was enjoying making movies and working with wonderful directors and just getting a big kick out of it, I was given this opportunity to do something for which I had no benchmark, no experience whatsoever.
"I threw myself into it full bore and it was a success. But I`m not quite sure how."