A retired Ministry of Defence engineer who left school at 16 is starting work as a teacher, at the age of 73.
Peter Tomkins, who has six grandchildren, has been a volunteer at Ryeish Green school in Spencers Wood near Reading for the past eight years helping GCSE students with their coursework.
Next year the school will be short of a specialist electronics teacher, so he has agreed to teach A2 and GCSE electronics (officially known as systems and control) for six hours a week.
"I'm one of nature's pedagogues. I still enjoy being involved in engineering, and I am still finding things to learn," said Mr Tomkins, who will be assisted in all his lessons by a qualified design and technology teacher.
"I'm not responsible for discipline so if there's any shouting to be done the proper teacher does that. I'm just there to help them and I think they appreciate that," he said.
Mr Tomkins has offered his service free - and will still keep Thursdays off for golf.
The school's technology teacher leaves for New Zealand this summer, but as his replacement is not an electronics specialist, Mr Tomkins has agreed to step into the breach.
Headteacher Jenny Garner is delighted. "In this area recruitment is very difficult," she said. "The students know and respect Peter Tomkins and he will give the new teacher training on the job. We are privileged to have a specialist who is willing to help."
Mr Tomkins became an apprentice after leaving Dartford technical college in 1946 and studied at night school to gain chartered electronic engineer status.
He first taught during his National Service then worked for the MoD for 33 years, continuing to teach adults at evening classes.
His MoD assigments included gathering electronically transmitted information from rockets fired in India, and measuring atmospheric emissions from French atomic bombs in the Pacific.
He is due to attend his Open University science degree graduation ceremony next week.
He first volunteered at Ryeish Green school through a scheme designed to promote electronic engineering.
"Engineering was a such good life I wanted to tell people about it - it is creative, interesting, and how took me all over the world," he said.
Students are enthusiastic about Mr Tomkins. Stas Blake, 15, said: "He reminds me of my granddad. Mr Tomkins is not like an ordinary teacher because he is very friendly. He is helpful and has a lot of knowledge."
"He's a great bloke and such a cute old man," said Tom Johnstone, 15.
"Thanks to him, I think I will pass my exam."