City College principal Peter Kaua said Uncle Bob's retirement was a big loss, especially for the kids struggling at school or struggling to find their path and sense of identity.
"In the Maori world we call Bob someone who goes beyond the rangatira and we call this tohunga.
"Because of his service and passion for learning, he doesn't have to order people like a chief does, or like I do, he just leads by example," Mr Kaua said.
But Mr Wilson's service goes beyond teaching. In the early 1990s he was the "king pin" in launching a transition programme that helped students cross the bridge from school to employment.
"It was a fantastic programme because it allowed students to explore career pathways and it was a chance for them to dictate their own learning.
"I spent a lot of time listening and talking about where they were heading. In my 42 years, there's only been five students I've not been able to press the right buttons," Mr Wilson said.
Mr Wilson said the result was that most students decided they needed to repeat year 13
because they hadn't thought about what they wanted to do.
"Now, we are finding less and less need to repeat because they are starting to think about it earlier and the programme has proved effective."
Back then, there were no guidelines and the programme was "very casual" until the ministry introduced flexible programmes like Gateway where students spend a few days a week working and a few days at school.
Mr Wilson said education had changed a lot since he first started teaching, and it was all for the better.
"It's become a lot more free. Students can work at their own speed and we just crack the whip on the ones that struggle to get motivated.
"Education has opened up to meet the needs of the students and is no longer bound by subjects."
A farewell assembly was held for Mr Wilson at City College on Friday morning.