Corden was overwhelmed singing "Let It Be" with the icon ... and we don't blame him.
We never thought we'd get emotional watching an episode of "Carpool Karaoke," but here we are.
The two returned to The Beatles' superstar's hometown, Liverpool, for the nearly 25-minute long video, driving around Paul's old stomping grounds to reminisce on making music and his humble beginnings.
After singing "Drive My Car" and the first song he ever wrote, a ditty called "I Lost My Little Girl," Paul explained how the genesis of "Let It Be" came to him in a dream. As he and Corden began singing the classic song, Corden got visibly emotional, tearing up as he harmonized with the music legend.
"I didn't feel it coming, it's too much for me. I didn't see that one coming around the corner," he said as he wiped tears from his eyes. "That's the power of music, it's weird isn't it? How that can do that to you," replied McCartney.
"I can remember my granddad, who's a musician, and my dad sitting me down and saying, 'We're gonna play you the best song that you've ever heard' and I remember them playing me that," Corden explained. "If my grandad was here right now, he'd get an absolute kick out of this."
McCartney simply replied, "He is," before the two sat a moment of silence.
From there, they visited McCartney's childhood home -- which he said helps him "realize how long the journey has been" for him" -- before the two drove around town again, singing one of Paul's new songs.
The trip ended with a stop at a local pub, where they surprised patrons with a performance they'll never forget. It all culminated in a group sing-along to "Hey, Jude," which may just be one of the most joyous things we've ever seen on late night.
Watch more memorable "Carpool Karaoke" episodes below: