Wilson-Walters said he and his younger brother went to live with their dad, Mason Walters, while his two younger sisters went to his nan in a whangai arrangement to take the pressure off the newly single parent.
It was then that he said he threw himself into the church, where he and his father spent a lot of time together.
Life was looking up for Wilson-Walters: he was a star basketballer at Rotorua Boys' High School and was getting himself into the workforce.
Then suddenly in 2015, his dad died of a heart attack.
"It was really sudden, it came out of nowhere. It was like one minute he was there and next minute, gone."
The death of his father shattered his world and Wilson-Walters said he went into a "really dark place" in the years that followed.
He left the church and turned to alcohol as a way to ease the pain, he said.
With the support of his wider family, however, he managed to get back on his feet and head in a direction he said his parents would have been proud of.
"I threw myself into my mahi and got back in touch with my faith by rejoining the church."
Now he is studying to be an electrician in Rotorua and hopes one day to own his own business.
The day he was born, a tree was planted at Rotorua's Centennial Park. A photo was taken that day with his mother and father holding him by the tree and a panel with their names on it.
"I hold that really close to my heart."
He said devastatingly, the panel had been lost over time and in spite of a number of visits to the local council he had not been able to track it down.
On his 21st birthday, he said he planned to give finding the tree another go as he wanted to sit by it and "reminisce" on the years that have been.
"It'll be interesting to see what's ahead for me. I know god's watching over me with my parents."
He laughed as he said his special birthday was "always a conversation starter" and people would always be impressed by it.
"I don't mind that, but I'm definitely not the attention type."
Caitlyn Gibson was the second baby born, and the first girl on January 1, 2000, arriving at 1.33am.
Gibson grew up in Rotorua, attending Selwyn Primary School, Kaitao Intermediate and Western Heights High School.
She was an avid swimmer and watersports fanatic and has gone on to study primary school teaching.
She said she would "go where the job takes her".
When asked what she thought about being a millennium baby, she said she did not think too much about it.
People were always interested when she told them her birth date, asking her whether she was the first and what time she was born, she said.