Is it normal that i got drunk off a few beers

I went to a campout and usually at campouts my friends and I would drink vodka, but for some reason vodka doesn't make me that drunk even if I drink a lot of it. So this next campout we went to my friend brought budweiser beer and I managed to drink 4 bottles. At first I was fine and then I kept blanking out and I got over emotional about everything, I also kept stumbling over every time I tried to walk. My ex who was there at the time said I faked being drunk and I'm not sure what actually happened because I have never really been drunk before and the whole experience is a blur. So is it normal to get drunk on just 4 beers or was I just having some sort of break down that my ex seems to think I had?