I used to never get hangovers despite giving my liver the alcoholic equivalent of a Tyson uppercut every week. That is, until my age finally caught up with me and my old tactic of chugging a glass of water in between every drink finally failed me.
A bunch of my friends were over and I shared my extensive liquor selection with them. We hung out all night and just never stopped drinking. At the very least, I drank at least two tall boys of high-gravity beer and at least one bottle of scotch, perhaps part of another one too.
That's what I believe, because at some point I blacked out and woke up in my bed still wearing my street clothes, sweating profusely and still somewhat drunk, with absolutely no recollection of what happened after 2AM. I then spent the rest of the day in the bathroom puking and shitting, and couldn't keep anything down that wasn't water, Pepto-Bismol, or bread.
It was at that point I realized I need to moderate my alcohol consumption before it kills me (that, and when you get older that booze goes straight to your gut and thighs). I now try to limit myself to no more than 2 or 3 drinks per day (pint of beer, ounce of whiskey, etc).