Why don’t I get hungover?

I’m an Australian and just turned 18. On Wednesday night I drank for my 18th, on Thursday it was my sisters wedding rehearsal, on Friday was the actual wedding and I went out on Saturday with the lads. All these nights I went so hard I was throwing up and passed out twice. The kicker I wake up with a clear head ready to go again. My whole family and grandparents are lifelong alcoholics so maybe genetics has something to do with it? Anyway just thought I would ask as none of my mates can relate. Anyway cheers guys let me know of any of you have and insite