The youth remembers going to one of the shooting victim's homes because they were trying to "de-radicalise me" before his offending.
He said that he didn't listen and looking back now he sees a "stupid, stubborn little kid who was angry all the time".
After 50 Muslims were massacred at the March 15 Friday prayers, the teen says he's felt "disgust", not just for those who died and at how much it has affected the nation, but also disgust at thinking of the harm he himself could've done to "innocent Kiwis" who are "his people".
Over the last three weeks, he's felt sad and now wants to apologise to everyone for "having such views of hatred".
"All I can say is thank you to everyone who gave me a second chance," he told Judge Stephen O'Driscoll.
Rehabilitation has "pretty much saved my life" and helped "clear my mind from a lot of hatred". Counselling is helping teach him methods to stop him feeling down or angry. He wants to participate in anxiety classes and an anger-management course.
On reflection, he can now see much progress he's made and wanted to tell the courtroom today: "I will never go back to extremist thinking or ideologies. All it does is cause, grief, anger and sadness".
What happened on March 15 makes him hate his "old way of thinking" even more and pushes him to want to be part of New Zealand society even more, he said.
He apologised for breaching his intensive supervision order – and had admitted using the phone the following day on both occasions.
Judge O'Driscoll accepted that it was clear he had not been using the phone or internet for any radical, extremist, or religious content.
Lawyer Anselm Williams said plans were ongoing to get the youth involved in some "meaningful activities" to help reduce his boredom, which Judge O'Driscoll encouraged.
A spokesman for Corrections accepted that he needs to be out in the community more.
Crown prosecutor Courtney Martyn said she was pleased with the boy's statements today, and noted how he's expressed an interest in speaking with people he'd previously met at a Christchurch mosque "because they were very kind to him".
The teen is due back in court for a further judicial monitoring session on May 10.