Apart from general questions about social norms, the basic problem with overdrinking is that alcohol generally boasts your confidence. Most people are already

Apart from general questions about social norms, the basic problem with overdrinking is that alcohol generally boasts your confidence. Most people are already really bad judges of how much they can drink before reaching various stages of intoxication while they are sober; it only gets worse when they're drinking. This is further complicated when mixing drinks with different alcohol contents. So while sober you might guesstimate that you'll be "pleasantly buzzed" after about three drinks. Then you have one or two drinks and your self-reflection skills get worse and you become convinced four or five is fine too and six is really only just a bit more than three, so that'll be fine too. It's generally an aspect of maturity to learn not to trust "drunk you" when asking yourself how much you should drink but humans are humans, so even adults screw up a lot.