Blues winger Tevita Li was the tournament's top try scorer with six, including a spectacular hat-trick in the 45-7 win over France in the semi-final.
Li struggled domestically this year with a poor Blues team but he's excelled at U20 level and his form has seen him nominated for the World Rugby's Junior Player of the Year.
"It feels awesome and it's a dream come true," said Li. "All the boys celebrated as we all do and it was a great feeling to be celebrating with a trophy in our hand.
"All our coaches have been awesome and to see them come out and be part of the boys and the team is awesome."
New Zealand topped Pool C with three wins from three over Ireland, Scotland and Argentina before their semi-final demolition of France.
Holders England were tough opponents in the final and New Zealand had to recover from being 10-3 down in the first half.
Robertson was critical of his young team's starts throughout the tournament but tries from Vince Aso and Akira Ioane led the fightback to see them win the title.
New Zealand Rugby can now focus all their attentions on preparations for the Rugby World Cup in England in September.
There's no doubt that some players will have made themselves known to All Blacks head coach James Hansen ahead of the tournament.
"Everyone's got their own ambitions but for now I just want to see family," said Moli.
"We've been away for a month but the now all the boys are just ready to chill and reassess things."
Li added: "There are a lot of good players in our team and I'm sure everyone wants to push on to bigger and better things."
