Brad Pitt thinks drinking beer made him a neglectful dad.The 'Ocean's Thirteen' star decided to massively cut down his alcohol intake after seeing his adopted daughter Zahara, two, choke on an ice cube. He said: "It's not easy to be a good father when you've had a few drinks."About a year ago I'd had a couple of beers and my daughter Zahara had this piece of ice that had been dropped on the floor, and she was putting it in her mouth and began to choke on it, and that was it."You have to be absolutely on top of every situation. The other s**t doesn't work anymore. When they wake up in the middle of the night you have to be there."And you can't deal with children when you have a hangover - that's just a misery!" Brad and his long-term partner Angelina Jolie have three adopted children, six-year-old Maddox, three-year-old Pax, and two year-old Zahara, as well as a 16-month-old biological daughter, Shiloh.The 43-year-old actor insists his kids find it difficult to cope with having famous parents. He explained to Total Film magazine: "It's odd for my children, man. They have this idea that there's this sea of people with cameras. This is their idea of the world they live in."