"We showed a lot of respect for all the teachers then and were wary of putting a foot wrong. Nowadays teachers are seen more as equals by students."
He went on to study at Victoria University before he went to teachers' college in Christchurch. His first teaching post was at Colenso High School in Napier.
This was followed by a move to Hauraki Plains College, Ngatea, in 1978 and then Pleasant Point High School, near Timaru, in 1985.
In 1989, Mr McKenna returned to the school.
"I've seen a few big changes since I was employed by the then- principal Joye Halford; Brian Lochore being appointed as Kuranui commissioner; David McGibbon, who originally taught me physics, acting as principal; Grey Tuck's years as principal and now Geoff Shepherd at the helm. But the biggest change has been in the use of technology and the construction of the new buildings," he said.
"The college is in great heart."