In 2012, he cursed his decision to let things lie when convicted paedophile James Parker was arrested at the school six minutes down the road from the intermediate.
"I could have prevented other young boys from being abused by James Parker," he said.
His teaching career was followed by a stint in parliament but in November 2013 the issue came to the forefront of his mind again when the Roast Busters scandal broke.
He decided there needed to be men in parliament speaking out against sexual violence and had planned to stand for re-election when he was called up in April 2014 to replace departing Labour MP Shane Jones.
"It's about using the position of MP to highlight the cause," he said.
He contacted the director of Maori sexual violence support service Korowai Tumanako, Russell Smith, and they lead a 440km hikoi from West Auckland to Cape Reinga, speaking at schools and communities about sexual violence offending.
During the hikoi, they set up an anonymous 0800 helpline number aimed at giving those who were having harmful sexual thoughts a way to seek help. Plans are already underway for a similar hikoi next year - led by Labour MP Adrian Rurawhe across Taranaki. Mr Davis has enlisted the support of National MPs Barbara Kuriger and Chester Borrows.
"This is cross-party, this is apolitical. It's just a good issue," he said. "I don't want to be the face of it. Everyone should be the face of it, it's about everyone doing their part."
He admits the ripples are small but "it's better to be doing something than nothing at all".