He also once shot the middle boy in the calf with an airgun while he played outside. It hurt him considerably and made him cry.
The boys were 9, 7 and 6 when he was charged.
The Auckland District Court was told how the two younger brothers were kept home when they were bruised meaning they missed "huge amounts" of schooling.
And after Goldie's offending was uncovered and they were put into their grandmother's care, she said the boys were fearful, scared, wary of people and withdrawn.
"They weren't the happy cheerful boys I knew before Charles walked into their lives. They didn't want to play outside, they were always scared to do things," she said in her victim impact statement.
But most concerning of all, said Crown prosecutor Nick Webby at sentencing, is how the brothers now think they can hurt others.
Once, the middle boy kicked the youngest in his stomach and when asked why he said that was how Goldie would kick him.
"Charles really hurt and damaged these boys and now these boys think they can do it to others," Webby read from the grandmother's statement.
Sadly the boys have been left with long-lasting scars, only some of which were physical.
"But the emotional scarring they've developed through the abuse will have a long-lasting effect throughout life, injuring their sense of self and ability to have healthy relationships and ability to function at home," their grandmother said.
THE CYCLE CONTINUES
Goldie said he was "beaten up" as a child and told a probation officer he "found it hard to see that using a wooden spoon was abuse".
And now those close to the boys - teachers, support workers and caregivers - say they're imitating the abuse.
The brothers, now 12, 10, and 9, also have serious behavioural problems, struggle at school, have issues with grief, aggression, anger and acting out, said Judge Anne Kiernan.
"And with careful care and supervision and a stable home environment, they are starting to make progress some three years on," the judge said before she sentenced Goldie.
"It's clear to me that each of these boys has suffered significant trauma and mental and emotional effects which will be the lasting effects that they'll need to cope with for the rest of their lives."
The cycle of abuse was unsurprising to the national manager of the Child Protection Education and Advisory Service, Amanda Meynell.
She said children who have suffered abuse or neglect can act out aggressively and violently or may become extremely withdrawn.
And the boys' struggle at school is also common because experiences of abuse and neglect impact on brain development and have lifelong consequences including poorer educational outcomes.
"Studies have found that those abused or neglected as children are more likely to suffer from mental health issues, have trouble developing relationships, and may engage in harmful and risk taking behaviours such as alcohol and substance misuse and criminal behaviour," Meynell said.
I SHOULD HAVE DONE BETTER
Ahead of his sentencing, Goldie wrote a three-page letter to the boys and the court explaining why he behaved the way he did - he thought at the time it was "for their own good".
"You said ... you wished you could go back and do things differently and be someone who strengthens his family, not someone whose actions have broken his family. You say you're ashamed," said Judge Kiernan, referring to the letter.
She then quoted the statement directly: "I thought in such a stupid way, like 'Hey, if I'm not giving them even a fraction of what I got as discipline then that's not bad.
"What a ridiculous mentality to have as a stepfather. I do know better and should have done better and been a much better stepfather."
THE SENTENCE:
Judge Kiernan said there was a "long list" of aggravating factors, including that there were attacks to the hit, repeated hitting and kicking, the children were particularly vulnerable and there was a significant breach of trust.
"They should have been able to depend on you for care and protection."
Goldie's case was before the courts for more than a year because at first he decided to defend the charges and elected to be tried by a jury in June 2015 but changed his plea to guilty the week his trial was set to start.
A sentencing date was then adjourned, Goldie changed his counsel and had another appearance adjourned to complete a rehabilitative programme from which he was exited for non-attendance.
He was then re-entered into the Man Alive programme which he completed before his sentencing last year.
THE ABUSE
The eldest:
Assault with intent to injure - sometime in 2013
He set off a firework so Goldie dragged him down a set of stairs then kick and hit him in his face, head and body.
Assaults child (representative) 27/09/12 - 12/11/13
Goldie hit him on his head and backside with his hand and repeatedly kicked him on and around his bottom and hips.
The middle boy:
Assault with weapon
Goldie stood inside and shot an airgun through a window, hitting him in the calf muscle while he was playing. It caused him considerable pain, making him cry.
Assault child (representative)
During the time period, Goldie repeatedly hit him on his head and backside using his hand. He also kicked him on and around his bottom and hips.
Assault with weapon x3 (representative)
Goldie repeatedly hit the three boys with a wooden spoon on their hands, backsides, the sides of their faces with some degree of force.
Assault child
The then 7-year-old was eating an egg but the way he was doing it annoyed Goldie so he grabbed it off the boy and threw it at him then stomped on it. He then threw another raw egg at him, causing it to break on his head and run down his face.
The youngest:
Assault child
Goldie hit the boy on his backside and head with his hand and kicked him around his bottom and hips.
INJURIES:
All the boys felt sore and hurt after the abuse.
