3 or four glasses of spirits, spread out over a "long" night, are not enought to even make a normal human a bit merry, let alone drunk (unless you have the constitution of a 5 year old).
If you drank soft drinks and water in between those 3 or 4 glasses, then there is even less of a reason for you to be drunk.
Fuck, you really are a weak person.
Only way 3 or 4 glasses of rum or whiskey etc would make me drunk, is if I did my old trick of drinking them within 20 minutes, and I dont even drink regularly!
American liquor is stronger than that watered down swill you're used to, I'm sure.