Looking at his work, she sought to make an encouraging comment. "That's interesting. So you'd like to be a carpet-layer?"
"No," he replied indignantly. "I want to be a corporate lawyer."
The story raises challenging issues about the relation between expectation, aspiration and achievement. Young people often receive conflicting messages from teachers and parents. On the one hand, they are encouraged to aim high, to have ambition, to be all they can be. On the other hand, they are told to keep their feet on the ground, not to get above themselves. Particularly in Scotland we are inclined to slap down those who are perceived as becoming too big for their boots.
Underlying these tensions are fundamental questions about the relation between schooling and work. Increasingly there are examples of people who achieve success in their chosen field without necessarily having done well at school. The list extends beyond sports stars and pop idols to include people in the arts, business, technology and politics.
One entrepreneur said recently that he would not hesitate to employ youngsters who had failed to conform to the academic and behaviour expectations of schools because they were likely to have more drive, initiative and creativity than their conformist peers. He was confident that he could redirect the energies of truants and rebels to engage in the kind of learning that would be valued by many employers.
For those of us professionally involved in education, this is a distinctly uncomfortable attitude to encounter. We have all enjoyed relative academic success and value what it has to offer. We want others to enjoy the same benefits.
However, this can lead to a rather narrow conception of what learning, and indeed life, is about. The richness and variety of experience represented by the world outside school is not adequately reflected in the curriculum diet that is usually offered, nor in the disciplinary regime that teachers are expected to enforce.
The result is that we can develop a dangerous kind of institutional narrowness that serves to frame and restrict our view of human potential.
Our defence often takes the form of saying that we have to prepare the majority of young people for the economic realities of life. These realities include the fact that - notwithstanding the line taken by the entrepreneur - many jobs are dull and routine: for example, work in call centres, the retail sector, the hotel and catering industry, computer assembly lines. But this is an unsatisfactory kind of response. The task of schools should not be to produce docile wage slaves: it should be to open up possibilities, rather than to close off options.
So what of the pupil who aspired to be a corporate lawyer despite his modest linguistic talents? Should he be redirected to a vocational course introducing him to the mysteries of Axminster, underlay and gripper rods?
Surely the first step should be to address the disparity between his present level of competence and the demands of the legal profession, set him the challenge to do something about it, and support and encourage him in his efforts. He may or may not succeed but at least he would have had the opportunity to demonstrate the strength of his commitment to a career in law.
Walter Humes is professor of education and head of educational studies at Strathclyde University.