Ben Affleck says Jennifer Garner helps him when he's scared by new project.

He said: "That terror when I'm about to start something can be motivating. It helps me kick my ass into gear, because I think, 'Oh my God, I'm gonna ruin this movie, I'm gonna not know what to do.'

"That's definitely a good, driving factor for me. My theory is that once you lose that, you're kind of going downhill ... [But] it's very trying for my wife.

"She's incredibly supportive and kind and patient with this, but I'll get into this thing of like, 'Oh my God, it's a f***ing disaster. This doesn't work, that doesn't work, I don't know what the f**k I'm gonna do.' "

Thankfully, his wife is a calming influence, and he admitted she is always "so on the money" with her assessment of the situation.

He told the Sunday Times newspaper's Culture magazine: "She'll just say, 'You said this on the last movie. You said it on the movie before.

"This is the point at which you go in there and listen to one song over and over again, and rewrite the scenes you don't like'. Then it's almost embarrassing, because she's so on the money."