korea's law of age

The law of age in korea states that the age of koreans will start counting once they are in the mother's womb. Just like we chinese, this means that when they are born, they are considered 1 year old already. In korea, the legal age to drink is 20. It's year 2010 now. This means that people in korea who are born in 1991 should be considered 19 years old after their 2010 birthday. But because of the law of age, they are 20 years old. On 8 Aug 2010, h-k will be considered 20 years old in korea while I am still 18 in Singapore.LOL