Everyone’s different. My ~70 yo father-in-law can knock back IPAs all night and go for a bike ride, bright eyed and bushy tailed, the next morning. Meanwhile I’ll have 2-3 light drinks and be grumpy and unmotivated the next day.
Yeah I didn’t really understand hangovers until I slowed my drinking down to reasonable levels, and then to barely at all. Now it’s not so much a hangover, but I notice I’m not really 100% percent for a couple of days after some drinks.