Anyone with Korean parents will probably tell you the same. But any flavor of hard-chargin' parents will probably have the same definitions for grades. Here's a table with the grade, the meaning of the grade in the education system, and the Korean meaning of the grade. The first letter of the Korean description matches the letter grade, in case you don't notice.
|Grade||System meaning||Korean meaning|
|C||Average||Cut off your head|
|F||Failing||Find another place to live|
Where I went to school, the grades seemed to be shifted a bit. B was an average grade, C was slightly below average, D stood for dumb, and F meant..well...F.
I am lucky to have never tested what would happen if I brought home a D or an F. One time in 4th grade, I got a C in math. My parents made me think that the fate of the universe might hang on that C. Nope, none of this "do your best and that's okay" nonsense here ;) More like "do your best or face the fires of Hades."
The only time that my parents were ho-hum about a C was when I switched schools in February in 6th grade. February is not exactly the beginning of the year, and one of the 6th grade subjects at my new school was Latin. So everyone else had about a 6 month head start, and I somehow ended up getting a C.