Julia Roberts has revealed people were "cruel" to her early in her career.

The Oscar winner admitted she had little confidence in herself when she first started acting.

"I don't think I entered into my career with much confidence," Julia, 57, told People Magazine in an interview published 8 October.

She explained that in her younger years, she had come across influential people in the industry who behaved badly.

"I encountered early on, not a lot but a few critical people who were really cruel," Julia recalled, "and it was a really interesting challenge for me to decide the kind of person I wanted to strive to be."

Those encounters, she said, left her contemplating her own legacy as an actress.

"So it was so much more about who I wanted to be as opposed to what kind of career I wanted to have," the After the Hunt star clarified. "And then I wanted to take the person that I wanted to build and put that person into these different situations of work life."

Admitting there were times when work was "so hard", Julia confessed she had experienced "more bumps than smooth sailing" between the ages of 15-25.

"Of course, even then, I would have shreds of gratitude. I would think, 'Okay, there's a reason why it has to be so hard,' " she reflected. "Now I look at it as some of the lessons that I'm the most grateful for because they proved my endurance to myself."