How do I know if I’m immune to hangover, or just not drunk enough?

Not a heavy drinker. Attended boiler room recently and I think I drank a lot… 2 beers to start, then 3/4 mixed drinks (vodka+sprite) and then 3 shots of vodka. All within the span of 2-3 hours? Was worried if I would get a hangover the next day (never got one).

Went back after the event around 3am and woke up around 9am, no headache, no hangover. Did I not drink enough? I’m not saying I should… just curious only.