"You can't just measure a child in a classroom situation between 9am-3pm," he said.
Mr Campbell's community has nominated him for a Pride of New Zealand Lifetime Achievement Award for an unwavering dedication to his students.
"You can ask anyone in the school their thoughts on him and they will be speechless. He keeps the school in motion and keeps its standards high," said his nominator.
Mr Campbell's teaching philosophies developed at an early age, mostly in reaction to his own schooling.
While he admits to being occasionally naughty at school, he still experienced some bullying and poor teaching.
This motivated him to to look after kids and do it "properly, without the old ways of control which are sometimes humiliation and degradation".
"All I do is treat kids with respect. It's no big deal," he added.
"A mother or family give [teachers] the most precious thing they have for five hours a day for 15, 16, 17 years, maybe. Teachers have an immense amount of power. If it's not used wisely and carefully, it can do far more harm." The students' career development programme is a significant area of interest for Mr Campbell, with impressive results.
During his 11-year employment at Maniototo Area School, every student has gone on to work or further their training.
"That's one thing I am very proud about in this school. [It's] a pretty good record, really."
Mr Campbell, it would seem, deserves the nickname his students give him - "the legend".
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Nominations for the 2015 awards have now closed.
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For more information on the awards go to the official website.
