One of the running jokes in the Simpsons is that Homer failed the second grade. "Ha ha ha!" laughs the American. "How can you possibly fail the second grade? What a looser!"
I'm not sure this joke would be as funny here, since failing in school seems to be no just a habit, but a way of life.
Social stigma is an amazing motivational force. In this respect, the Spanish system seems to be the completely opposite of the Chinese, who spend their entire youth studying for that one big exam that will make or break them.