1) Money. It makes me cringe when I realise how much money I'm litterally just setting fire to and burning away. And every time there's a budget it all goes up again.
2) I'm a singer, and I've come to realise that smoking is wrecking my voice. I want that back.
3) Health. There's a bloke I know at my local pub and he's dying of lung cancer, but he doesn't quit. He goes round the beer garden outside, asking people if he can cadge one off them. And I looked at him coughing this week, and I realised that if I don't do something now, that might be me in 15 - 20 years.