I think blacking out and forgetting is just bullshit to use as an excuse in court, or to explain to your girlfriend that you didn't remember sleeping with some other girl.
Its definitely not bullshit. I have two nights that I have notable gaps in and could not tell you what happened. For example: I have absolutely no idea how I got from the club back to the hotel room for my friends bachelor party
i know when to stop because i hate throwing up.
If you drink enough throwing up is not so bad as you don't really feel it or remember doing it.