I haven't always had this problem, I graduated college and started eating healthier, not drinking much at all. I'll go out with my friends every once in a while and I'll have no more than 4 drinks and my night will be blurred and I'll forget things here and there but remember things that happen before I go to bed. But I will most definitley blackout for atleast a half hour at a time. I used to be able to have 12 drinks and be dandy! I'm a chick, petit and can't think of any reason as to why this is happening

When you forget or black out like that, it means something isn't going quite right in your brain. Could be the alcohol overload, or it could possibly be a more serious reason. I'd lean strongly towards the former, but if you cut back and still black out, then perhaps you should see a doctor to make absolute sure you don't have any serious brain damage.