Sounds like you just keep hydrated and get sufficient electrolytes while drinking. Unless you are like blackout levels of drinking hydration, food and electrolytes will keep you in action from my experience. The other thing is when do you drink, if you drank real late your gonna be intoxicated while trying to sleep which would kill your ability to get deep sleep and rem sleep which are the stages that promote physical and mental recovery. Fuck with that and don't stay hydrated and fed while drinking and you are in for a bad time, regardless of age. I think in your twenties your more likely to also be crawling bars which means you have food and hydration options readily available that your probably gonna have in addition to the alcohol so the main issue becomes lack of rem and deep sleep creating a mild hangover for most early on. Also as you get older, you're more likely to hurt yourself doing something you felt invincible doing in your 20s so that physical recovery stage becomes ever more important cue worse hangovers. But im not a doctor, so if I'm off here on any of my explanations, please correct me.