Keira Knightley worries about her behaviour after a night of drinking.

The 28-year-old actress admits she gets paranoid about what she may have got up to after spending time with pals and often thinks alcohol makes her ''really rude''.

She told Metro newspaper: ''Oh Christ, I'm always apologising for when I think I have been 'off' on a night out. The next day you suddenly think: 'Oh my God, I think I was really rude.''

Drinking isn't the only thing Keira - who is married to Klaxons keyboardist James Righton - gets paranoid about, as she claims her busy schedule and jet-set lifestyle make her worried that she may one day appear naked in public after forgetting to put clothes on.

She laughed: ''I flew into LA from London, straight into hair and make-up, straight onto a red carpet and you think: 'Am I dreaming one of those dreams where I've forgotten to put my dress on?' And you keep looking down, going, 'No, it's all right, I'm wearing clothes!' ''

While Keira worries about the effect drinking has on her, she recently admitted she would turn to alcohol if the world was about to end.

Discussing what she would do if the apocalypse was near, she said: ''We'd be dancing a lot and drinking a lot of [alcohol]. But not beer. I don't like beer. Wine, vodka, whiskey ... anything to make me forget about what's happening outside. I wouldn't want to be sober at the end of the world. Oh, and we'd get some chocolate cake and eat until the world exploded.''