One of the devilish features of the enjoyment of alcohol is that it likens itself to excess. You tend to drink it in a social setting and that setting makes it more fun to drink and then the drinking makes the actual social occasion more fun in turn. It also, obviously, feels good while you're drinking it and getting drunk, which tends to make you want to drink even more of it because you're enjoying the experience so much. On top of that, obviously, it makes you drunk, and as you probably know, being drunk doesn't tend to make for very good decision making so thoughts like "you might be enjoying this a lot, but you should stop now, then you won't be sick tomorrow" tend to give way to "nah I feel fine right now, so it'll definitely be a good idea to have another and definitely won't be a terrible idea come tomorrow. Also, that's tomorrow's problem anyway".

Have a hangover enough times in your life and this dynamic happens less often since even the drunk happy version of me remembers somehow the deeply unpleasant experience of a hangover from last time and stops before it's too late but unfortunately, every now and then the lesson has to be re-learned.

Because drinking is fun.

Also I have no self-control in the moment. You don't think about the hangover while you're drinking.

I do not drink very often, but when I drink I want to feel something from the alcohol. Also I would never drink beer out of a cup.