Chris Hemsworth accidentally stabbed himself when he was younger.

He explained: "I remember the sales guy asking, 'Well, what are you gonna use that [knife] for?' I said, 'Fishing?' And that was the security test.

"Later, I went snorkelling in this swimming hole. Thought I stabbed a fish, but I stabbed myself in the hand instead.

"I still have a vivid memory of what that felt like. It wasn't alarmingly bad, but it was like, 'Oh, wow. I've just done something here.'"

Meanwhile, the 31-year-old actor also admitted that he has no "empathy" for his younger brother, Liam Hemsworth, 24, despite being just as "reckless" when he was younger.

He said: "I've watched Liam do things I did at his age, like being in relationships he shouldn't be in, or being reckless just to prove a point. And I had no empathy. My mom had to remind me I was the same way."

Chris - who has two-year-old India and twins Sasha and Tristan, nine months with his wife Elsa Pataky - also praised his older brother, Luke Hemsworth, 34, for helping to save his career.

He told America's GQ magazine: "Back when I was still on the [Australian soap 'Home and Away'], I became incredibly insecure and full of anxiety because I didn't know if I was any good. Yet I wanted it so bad.

"I spent years being angsty, constantly telling people I wasn't just part of a soap opera, that I was a real artist. And I remember Luke sort of snapping, telling me to shut up, that he was sick of hearing it."