When Matt Hall mistakenly dived into the shallow end of his friend's swimming pool he knew instantly what he'd done.
The father of two had snapped his neck, leaving him a quadriplegic.
But as his body stopped working his mind went into overdrive, delivering what some might call a miracle.
For the past year he has been building towards the goal of walking unassisted and the journey leading up to letting go of his crutches is astonishing.
The 39-year-old has kept only one image from his time in hospital, he doesn't like reminders of what he calls his darkest time.
His C5 C6 dislocation meant he was paralysed from the neck down.
"I truly had a blind belief that I would get through this, it seems crazy to think like that," he said.
"I didn't want to know, I knew enough but once you start to learn too much it starts to cause more limitations and you see what hasn't been able to happen rather than what can."
In May 2017 Mr Hall began daily sessions of NeuroPhysics Therapy in Auckland.
In simple terms the therapy is designed to clear the body's internal message system. Mr Hall has made rapid improvement.
"People don't believe me that I had my injury, they think I'm telling stories on it because now they see me on crutches," he said.
"I don't think they realise that is was only seven months ago that I was in an electric chair."
Mr Hall used video to document his progression building his strength to support himself, eventually able to use a walking frame and then two months ago on to crutches.
Not that he wants to look back.
"A lot of people like to say look where you've come from but for me I see everything thing that I'm not yet," he said.
"They say you're up and walking and I say no I'm not, so I see what I need to do next and what's the next step."
And that next step is literally just that.
After a year away from his teaching role in Singapore Matt Hall is walking again, with perhaps the greatest lesson to share with his students when returns next week.