James McAvoy insists being an actor prevents any sense of ego.

The 'Glass' actor admitted nothing brings him down to earth more than when he puts in a passionate performance, only for the director to call cut and for him to realise no one on set was paying him much attention.

He told Men's Journal magazine: ''Sometimes, when I'm acting on set, I feel like I bare my soul and f***ing reveal the deepest darkest truths of my upbringing, and I do what I think should be a nominated performance, and then they shout 'cut,' and I'm like, 'Uh?'

''You look at the crew, and everybody's picking their nose or scratching their balls at that moment.''

The 39-year-old actor - who has eight-year-old son Brendan with ex-wife Anne-Marie Duff - insists he doesn't do anything to ''deserve'' attention and he believes on photoshoots he is just treated like a ''flighty horse'' because people are determined to get as much out of him as possible.

He said: ''I mean, everything gets normalised after a while.

''But what you've got to do as it's getting normalised is to remember that everybody just has their role to play.

''And even though I was the focal point this morning, that's just my role. It's not like I deserve it.

''And by the way, nobody else who was there is f***ing thinking to themselves: 'Wow, what a guy!'

''It's just because they've got you for such a small length of time.

''I think they think of you as sort of a flighty horse, almost. If you don't treat it with f***ing kid gloves, it's going to buck and run away and you'll never tame it.

''Because they've got a very finite amount of time to get a lot of content out of you. There's a lot of internet to be filled up. Do you know what I mean?''