The reason David's parents remained in the dark was not bashfulness or forgetfulness, but concern for his twin brother, Scott.
The 13-year-old's mother, Margaret Sloan, explains: "David was playing down his achievements because he didn't want to upset his brother. He would come back with letters of commendation and wouldn't tell us about them - they would just stay in his bag.
"I would probably find it at the end of the week when I took out his gym kit. I'd say, 'You didn't tell us about this', and he would say, 'But Scott didn't get one'."
For some years David had been doing well at school, while Scott had struggled to get to grips with some lessons. Scott's difficulties made him upset and stressed, while there was tension between him and David that led to frequent squabbling. Being part of the first Wallace Hall cohort of second years to begin Standard grades a year earlier than the norm, therefore, was a daunting prospect.
Living up to its intention of providing a flexible curriculum, the school suggested that Scott do only seven Standard grades. He decided not to take French, and spends the extra time working on weaknesses in other subjects.
Scott takes much of the responsibility for deciding what to work on and, through e-learning with the help of a support for learning teacher or assistant, has made dramatic progress.
"The strange thing is that he seems, in class, to always be behind, but when it comes to exams, he's getting the marks," Mrs Sloan says. "I really feel it's because he's getting this time in e-learning, and the teachers are re-inforcing the areas that he hasn't grasped in class."
At home, too, there have been improvements, with the twins getting on better now that both feel satisfied by their progress at school.
Mrs Sloan, who recently became vice-chair of the school board, felt that the best efforts of Scott's "very excellent" primary school were hampered by curricular pressures. By allowing Scott to take responsibility for his learning, she believes Wallace Hall is helping him reach his potential.
"They always told me through primary that the penny would drop," she says.
"It's been very late in coming, but that penny has at long last dropped, and you've got one very happy parent here."