Mike Stangle (left) and Dave Stangle, the original Mike and Dave. [Photo provided to China Daily]

A lot has stayed the same for the two, who grew up near Albany but went on their dating rampage in New York City, where they were living that crazy summer. They've still got regular jobs, for instance. Dave, at 31 the older bro, pushes pet-themed products for a box delivery service and Mike, 27, is a bartender in Brooklyn because, health insurance.

But some things have indelibly changed. For starters, when they visited the movie set in Hawaii to hang out and shoot cameo roles, Kendrick yelled at them to whip out their you-know-whats.

"She did. I think she pantomimed," said Mike.

Dave deadpanned: "I was like, do we have to? I'll do it if I have to. I didn't."

Mike: "She was going full method into her character."

Dave: "I was, like, you don't want to see this. It's not good."

And so it goes as the brothers help promote the film and try to figure out their next move, which - they say - hopefully will involve more writing.

"We've really just held on for the ride and enjoyed every part of it from the same seats we were in before it happened," Mike said of their viral-turned-Hollywood riches. He added: "We have to kind of remind ourselves that it's a dumb-luck crazy thing."

Crazy, indeed, as they so chronicled in their wry but oddly touching book that takes on details of their dating escapades and other adventures, offering their parents props for putting up with them.

The movie takes license, they said, but gets some key stuff right.

"The family dynamics and the characters are very true and representative of us, and that's really all we wanted," Dave said. "They've included enough of our stuff that we kind of deferred to them on what's going to make the movie great, and they did it."