"It was how Prime Minister John Key reacted to these terrible tragedies, particularly the one closest to my heart, where I first began to truly respect him, and appreciate him as a remarkable leader."
Key made a four-hour return car journey from Hokitika to Fox Glacier to visit the crash site and pay his respects, an act which inspired the then 15-year-old Millar.
He wrote to Key, thanking him and asking for advice for his own future.
"I was amazed to receive a very personal letter back directly from the Prime Minister. Not only did he address all of my points issue by issue in an extremely kind and personal way, but he also enclosed a card, saying he wanted to meet me."
"I remember thinking, 'if he could, why couldn't I?'"
Several months later Key visited the Millar family home in Greymouth, where he was served whitebait sandwiches and a cup of tea, and chatted with Millar about the future.
"He didn't publicise the visit for political profit. No media were invited. He did it out of the goodness of his heart, because he wanted to help, and because he cared.
"It was the goodness of John Key's heart that inspired me to try my hardest in life, and strive to be the best version of me that I could be," Millar wrote in the LinkedIn post.
Millar knew Key had also lost his father as a child and was inspired the father-of-two still achieved his childhood dream of being Prime Minister.
"I remember thinking, 'if he could, why couldn't I?'"
After working hard to be head boy of both Christchurch Boys' High School and his boarding house, he turned down a $40,000 law scholarship to launch the start-up OOMPHER.
The startpup was acquired by Careers New Zealand, a Crown Entity of the Government, in May last year, 10 months after its launch.
A second start-up, Unfiltered, followed and Millar now spent his time travelling the world, interviewing "the biggest names in global business", includingVirgin founder Sir Richard Branson.
"The point to all of this is not that I'm something great, but that it's all been inspired by that early spark of inspiration - when John Key wrote to me. Whether you loved or hated his politics, as Prime Minister, John Key was a good man. He had integrity. He cared about the people he represented.
"He did the right thing, even when no one was watching."