Lui

I was born in 1987.

　2010

-1987

= 23

+1year

( 10 months -> inside in mother + hundredth day ->when 3 month after born)

so when the baby is three months old is grow a year older :-)

therefore I'm 24 in korea

but I'm 22 in another country (because not pass my birhday)

Is difficult...? X_X