"You hear records that were popular at certain times, especially back in the 90s and early 2000s, people were jumping on these fads and trying to get a quick hit," he exclaims.
"We never did that. We were very conscious not to do that."
I join in the fun and jokingly ask Cool why Green Day never added a DJ or rapper into their three-strong mix, which has never strayed from him, front-man Billy Joe Armstrong and bassist Mike Dirnt.
His chuckle gets louder.
"That's a good example ... We were very careful not to jump on any sort of sonic fads ... We left all the cheap tricks to other bands that have long since gone."
His tongue is firmly in his cheek. In fact, over a casual 15-minute phoner, it becomes apparent it might live in there. "My wife is over there decorating her backpack," he says at one point during our conversation. "Check her out. Aww, she's adorable."
But his joking takedown of nu-metal is a solid reminder of the timelessness of Green Day's 1994 album Dookie, their snot-fuelled cartoon punk blast that kick-started a career that's now into its 31st year.
Despite a career that's morphed into politically charged albums like 2004's American Idiot and last year's Revolution Radio, hits from Dookie - like Longview, Basket Case and When I Come Around - are still the highlight for many during Green Day's live shows.
That's likely to be the case when Green Day hit Spark Arena with The Interrupters this weekend.
And Cool is, well, super cool about that.
"I remember when we wrote and recorded them ... the common thread was always longevity. We kept saying, 'Let's make something that doesn't sound dated. Let's get a quality recording, record what we sound like, make it about the songs, make it about the performance, make it about the band."
Dookie songs are still a favourite for the band to play too, admits Cool.
But not for the same reason.
"I notice when we start playing those Dookie-era songs, you smell the aroma of marijuana in the audience every time, no matter where you are. Even in Texas," says Cool.
"It's cool, like, 'Oh yep, the old-timers are lighting up their joints' ... you get a free contact high with all the Dookie stuff."
The other highlight of Green Day's live shows is their 20-year tradition of jamming with a superfan. Despite some occasionally woeful performances, Cool says Armstrong's fan choices - chosen randomly from the crowd - are usually spot-on.
"He'll look around for someone who has a snap factor, someone who's a little bit off. I don't know how he does it, but it's always different people. Half the time, I'd say it's amazing, good, probably another 45 per cent, and 5 per cent would be, 'They just can't play'.
"That grade point average would get you into most colleges," he laughs. "It's pretty good odds."
But, he warns, if you want to get picked from the crowd, there's something you should never do.
"Having a sign does not help," Cool says. "I've never seen Billy pick anyone to come up on stage [with a sign saying], 'Hey Billy, pick me'."
Cool's got another warning too. This weekend's shows - on Saturday and Sunday nights - will be very different from each another.
"The second night is going to be completely nuts, because it's the last show we do with The Interrupters," he says. "We have a tradition to play lots of pranks on the opening act on the very last show. That will be the Sunday. So if you really want to see a special show, that's the one to go to," he says.
"I cannot give anything away, but we have a long tradition of hi-jinks and onstage pranks during their set."
There's another hint of a mysterious chuckle from behind his hand again. Then Cool declares: "Don't come late."
LOWDOWN
Who: Drummer Tre Cool
What: Punk-rock veterans Green Day
Where and when: Spark Arena, Saturday and Sunday
Also: New album Radio Revolution, out now
