Soju, Me too

I don’t know how alcohol percentages work but if I drink Soju, that is 16.9%, and Modelo, that is 4.4% alcohol, am I drinking a stronger 16.9 or am I drinking over 20%? I have polished off a bottle of Soju so my brain is a little blah blah right now. My friend told me that people don’t pour their own drinks in Korea because it will cause a person to be single for three years. Yikes!