"I suppose my mates would know that and I don't know if I show it out on the field but there's a lot of things going through my head, and I try and keep my emotions to myself and all that," Barrett said.
"So, I suppose if you really know me you'll understand the ins and outs, but other than that I'm pretty laid back.
"If you're a first-five that is sort of up and down in emotions and really panicky and players look at you, they don't really trust you. So you've got to stay calm and you're the one calling the shots alongside of a couple of other players so you've got to be pretty calm and level-headed."
Barrett spent three weeks with the All Blacks during the Irish series as well as the extended squad training camps that were squeezed in during the earlier stages of the Super Rugby season, and said he had picked up a few tips during his time working with players like Dan Carter.
"Just seeing how they operate. They're very professional and they put a lot of expectation and pressure on themselves to do the job and just the way they go about their work during the week making sure they tick everything off, so when they get out there on Saturday they can just enjoy the moment and trust they've done the work and play the game."
The Hurricanes will be without halfback TJ Perenara, loose forward Victor Vito and wing Cory Jane for tomorrow's (Saturday's)
game with the Crusaders, but Barrett said he had faith in his combination with replacement No 9 Chris Eaton to flourish.
"It's been good all year. He's been around for a long time, got plenty of experience and he's got a good pass, so I'm looking forward to this weekend and playing alongside him."
Tomorrow's game is a must-win for the Hurricanes who are in sixth spot in the Super Rugby standings, but only one point separates the next three teams meaning they need to keep up the pace as they pursue a spot in the playoffs.
The Crusaders will be without All Blacks Kieran Read, Israel Dagg and Carter for the game.