I adopted Gordon when he was 10 years old. He had had a traumatic early family life and had never been to mainstream school. In various "care" institutions, he learned that a stance of helplessness was rewarded by the adult attention he craved. He came to me unable to read, write, dress himself, tie his shoelaces, tell the time or concentrate on any task for more than a few moments.
The professionals involved suggested he attend the local school for pupils with "moderate learning difficulties". Yet there was something about his advanced language development that made me doubt this assessment and I argued for a mainstream placement.
"Thank you, Mum," he said. "I just want to be a normal boy. I want to have potential."
After five rather stormy years of schooling, including two exclusions, he attained one Standard grade 1, in English, and went on to an agricultural training scheme. Some of his teachers deserve sainthood. They worked miracles and were justifiably proud of his achievements; he had been so close to becoming what we now call Neet.
Since then, Gordon has worked mainly in agriculture, on minimum income. It has taken him another 20 years, and a major change in circumstances to review his potential and to believe he can do more. He is experiencing a short period of unemployment and has attended an adult career day course, consisting of some group work and psychological and work skills profiling.
He shared with me a print-out of his work skills, attitudes, work potential and personality, and we discussed options for higher education and training.
"I just didn't know I had all this ability," he said. "I'm surprising myself."
Gordon tells me he wants to study psychology and work in early education. "I want children who are all mixed up, the way I was, to know that they have promise - that normal life is for them too."
I watched him at Christmas finger-painting with his two-year-old daughter, and I am ashamed I did not realise that he had such ability.
It has been my privilege to work with many of today's teachers who perceive that some of their most challenging pupils have hidden promise, and who are tirelessly creative in helping them find it. I believe we are so much better at recognising potential than we ever have been.
There is a huge challenge, however, for those who manage and inspect our schools to value and evaluate this aspect of the craft of teaching. Like finger-painting, it is all a bit messy - but worth the trouble.
Jeannie Mackenzie is director of Conditions for Learning, an education consultancy.