Somewhere between old enough and too old.

53 Korean age, which tells you immediately that I was born in 1968.

59 or 60, depending on who I'm talking to. Born in early 1961.

Guess.

One thousand nine hundred and eighty six?! Damn... What's your secret?

yeah true i guess im 26 in korean age  call me 행님

I see we have been gathering data here recently on waygook.org.

Next you'll be asking for the name of my first pet.

Be vigilant folks.   

As old as my tongue; a little older than my teeth!

As old as my tongue; a little older than my teeth!

Miracle on 34th Street! Great movie.

theman, Is this actual, real, official, accurate, truth age? Or kOreAn 'AgE'?

You really can't figure out the application of a different system, can you?

I'll try once more.

If you tell me your western age, I need more information to determine your birth year. For example, if I state that I am 52 (western age) I could be born in either 1967 or 1968 depending on whether my birthday has passed or not this year.

However, with the Korean system, by stating that I am 53, you can immediately assertain that I was born in 1968 regardless of whether my birthday this year has passed or not.

A systems efficacy, and precision is measured against the goal desired.

If you want to know how many orbits around the sun have been completed since birth then the western system works better. If, however, you don't care about orbits, but rather,  in what year someone was born in the most efficient manner-fewest questions necessary-then the Korean system is better.

The goal of asking someone's age in Korea is to determine the year they were born and the Korean system works better for achieving this goal.

Western system:
A: How old are you?
B: I'm 52. (Could have been born in 1967 or 1968)
A: Did you turn 52 this year or will you turn 53 this year?
B: I turned 52 this year.  (A now knows that B was born in 1968)

Korean system:
A: How old are you?
B: I'm 53. (A immediately knows that B was born in 1968)

See? Not stupid. Just different cultural goals that a different system meets efficiently.

However, with the Korean system, by stating that I am 53, you can immediately assertain that I was born in 1968 regardless of whether my birthday this year has passed or not.

In my experience it doesn't really work like that though. When Koreans hear someone's age, more often than not there is a confused look on their face. They are trying to run the numbers through their heads so it results in a few second pause. Even after this, very often they would follow with a "So what year were you born in?" And it's not because I'm a foreigner so they are unsure whether I told them my western age or Korean age. I see this happening a lot between Koreans too. So I wouldn't say they know it immediately.
It's the same the other way around too. My wife always needs to do some counting to figure out how many candles we supposed to put on her parents' birthday cakes. She knows what year they were born in but she doesn't seem to know right away how old that makes them.
It's far from efficient.