Two things made Sandy Grassie happy: stretching the limits of his ability and imparting knowledge to others. His struggles with the first, the academic-turned-schoolteacher said, meant that he particularly valued the importance of the second.
Alexander Grassie was born in Aberdeen in April 1935. When teenaged Sandy displayed a talent for French, his teachers attempted to persuade him to study the subject at university. But French came too naturally to him: he wanted more of a challenge.
He opted to read physics at the University of Aberdeen and then went on to Queens' College, Cambridge, pursuing a PhD in experimental low-temperature physics.
While at Cambridge, he was invited for dinner by an old schoolfriend. The table was crowded and included various student-newspaper editors. When one guest, Tricia Franklin, turned off the heater in the corner, Sandy smiled at her. "I think there's enough hot air in the room already," he said. They married a year later and went on to have three children: Andrew, Robert and Kirsten.
In 1962, Dr Grassie was invited to become one of the founder members of the physics department at the newly established University of Sussex. Tall and broad-chested, he exuded a confidence that was not always backed up by reality. "If I can do something, then I don't feel it's worth anything," he would say. And so he pushed himself to the limits of his ability, deliberately seeking out apparently insoluble problems.
As a result, he understood how difficult learning could be. This led to an interest in school science education and he was eventually seconded to the Nuffield Foundation for Science Teaching to help develop a broad A-level science course.
Dr Grassie felt keenly that schools were full of untapped potential and he wanted to help them realise it. He began running one-day workshops for physics teachers, to show them what and how undergraduates studied at Sussex.
He also found the teaching element of his job increasingly rewarding. He was never happier than when his students challenged him. Then, he said, he knew he had done his job well.
He was a man of compassion. When a partially sighted student applied to do experimental work at Sussex, many in the department were wary of the commitment this would require from a supervisor: Dr Grassie volunteered immediately.
In 1990, he took early retirement from Sussex and was appointed head of physics at nearby Roedean School. Although teaching at an independent school jarred with his egalitarian principles, his lack of teaching qualification meant that he could not work in a state school. And, in fact, he flourished at Roedean with pupils who desperately wanted to learn.
He retained his compassion. Later, when he became ill, his concern was not for his own health but for whether his nurses were overworked. He would become angry whenever he witnessed other patients being rude to them.
Sandy Grassie died on 17 November.