In fact, when asked how long it had been, he said, "Neither of us could remember, which I think is a sign that it's been quite a while." That's not to say that he doesn't remember her from the show, though. Far from it.
"I remember when we first got to the show, they sort of had all the kids perform for one another," he recalled. "I remember it was Christina Aguilera and then Britney performed and I remember thinking, 'Okay, so they're like freakishly talented.' I was used to working with talented people but that was another level."
When Ellen asked what Gosling did to follow up their next-level performances, he joked that he just kind of stood up and said, "I'm Canadian."
While the pair didn't reunite in front of the studio audience, they did reconnect briefly backstage, with "Ellen" capturing the moment with a few pictures.
While Spears was there to just quickly announce an upcoming announcement, Oct. 18 on Ellen's YouTube channel, Gosling was there to talk about his upcoming film "First Man," where he plays Neil Armstrong. And as anyone who's followed Gosling's career knows, he likes to immerse himself in the characters he's going to play.
He's shadowed teachers and lawyers for previous roles, so for this one, he thought he'd go ahead and learn to fly. "Neil was flying before he learned how to drive so it felt like something I should learn how to do," Gosling explained.
"And if I'm honest, you always hear about celebrities flying, so I thought, how hard could it be. If celebrities can do it, it's gotta be--"
But he cut himself off there and said simply, "It's very hard."
Actually, it sounded like things were going quite well indeed until he got to the point in the lessons where the instructor asked him to put he plane into a stall, triggering a freefall. "He said let's put it into a stall, and I thought, no, let's land and I'll spend my time learning other things."
Suddenly, he lost all interest in flying.
He nevertheless was still able to embody the famed astronaut, with critics lauding this as one of his best performances yet. Gosling gave at least some of the credit for that to the spacesuit he gets to wear. And it was great for more than just getting into character.
"I loved this suit, because no one talks to you, you don't have to talk to anyone," he said. "If you have any kind of social anxiety, I highly recommend a space suit."
Check out Ryan Gosling in all his spacesuited glory with "First Man," in theaters now.