Why do I act so differently and unlike my normal personality after drinking alcohol ?

Last weekend at a party I drank more than usual and after about a quarter-and-a-half of consumption I started behaving very erratically — I poured water on all my friends and it turned into a fight that was only settled the next day. I would never do anything like that sober, so I’m really puzzled and scared: psychologically, is this kind of post-alcohol behavior a true manifestation of something inside me (a hidden side of my personality) or is it just the effects of alcohol disinhibiting me? How can I understand why this happened and make sure it never leads to unintended consequences at future parties? Any explanations, personal experiences, or practical steps to prevent this would really help.sorry for the long passage , this is my first question in here /