This version of the character was brought into A.N.B.U. around the age of 4. Grown adults, who have actually had a childhood before going into certain branches of law enforcement struggle to "act normally." To the point where there is even a spot the fed meme. It's completely believable for this version of Naruto to over act like this.
It's the sort of thing that needs to happen if someone goes undercover. Breaking cover, at any time, and for any reason, can be more lethal than anything else.
