Again, Brett's childish and drunken testimony shows what a shitty adult he grew up to be.
The thing about alcohol is that when you start drinking it at an early age, as Brett did, it stunts your emotional development. When you bringe drink at an early age, so much to the point of blacking out regularly, the health effects start permanently impairing your judgment and brain chemistry so that your brain develops a dependency. Your brain is still developing well into your 20's. Flooding it with alcohol will distort or warp that development, producing an arrogant, belligerent, childish asshole we saw last week.
I hope he is honest with himself and gets the help he clearly needs. Don't be surprised if by this time next week, he's giving a teary press-conference and checking himself in to Betty Ford or Passages Malibu.