Dunedin - England lock Tom Palmer was the one giving the lessons when he took time out from the Rugby World Cup to return to Otago Boys High School on Monday.
Palmer, one of several England players taking a coaching session, was a pupil at Otago Boys and played in the same school team as current New Zealand captain Richie McCaw.
A photograph of that 1997 side, which included another player appearing at this year's World Cup in Fiji's Filipo Levi, is still on display in the school.
Founded in 1863, Otago Boys is one of the oldest schools in New Zealand and has produced 23 All Blacks.
Palmer spent the bulk of his schooldays in Scotland, where pupils generally take 'Highers', the final school leaving exam, aged 17 whereas in England the equivalent 'A-level' is usually sat when students are 18.
"I was in Edinburgh and the main reason to come here was to play rugby because New Zealand is the country for rugby," Palmer, who went on to study physics at Leeds University in northern England, said Monday.
"My coach in Scotland received a call. His brother was a SRU (Scottish Rugby Union) official and he knew a guy here who was trying to exchange players between Britain and New Zealand.
"He spoke with the school and they said 'yes, we want players'. I was 16, almost 17 and I played two seasons here, the second with McCaw because he was a little bit younger.
"He was a good player, but not the star of team. But the year after I left, he came on leaps and bounds."
It was at Otago Boys where the now 32-year-old Palmer was converted from a back-row forward to a lock.
"The first season I played number six and the second season lock, because we had an athletics session and when the coach saw me running the 200 metres, he told me to go to the second row."
In 1997 Ryan Martin, now a teacher at Otago Boys, was the school's scrum-half and he remembers Palmer from their days playing in front of crowds of up to 3 000 spectators, such is the level of interest in schoolboy rugby in New Zealand.
"Tom played two years here and even played for New Zealand Schools, which is a big achievement," Martin said.
"I called him last week and we went out for a lunch here in Dunedin. He was a year older than me but a good team-mate."
Brian Ashwin, the coach who converted Palmer into a second row, said on Monday: "He's got a lot bigger since he left school. Now he is huge.
"He had finished high school in Edinburgh and came for a year to play rugby before going to university in England, but he stayed an extra year."
"He was always tall, but quite slim when he started here.
"For him it was quite an introduction to the physicality of rugby.
"He was our go-to-man the line-out for two years. He was really mobile, made a lot of tackles and had great aerial skills."