The first effect of alcohol is APATHY. The apathy begins immediately. With apathy the person does not realize their condition any longer. That is when they do acts that are not rationally motivated. That is why you sbould never drink alone, i.e. without a sober friend next to you and holding your car keys to make sure you get home safely..
Actually, the first effect of alcohol is REPETITION. Drunks say the same things over and over again. (Just kidding. :-))