Paul McCartney was the sole guest Monday night on "The Late Show with Stephen Colbert" and, during a wide-ranging interview, he revealed that he often dreams about John Lennon and playing with his old group.

McCartney explained that it's not unusual to dream about somebody with whom "you've had a relationship like that for so long, such a deep relationship."

He continued, "I love when people revisit you in your dreams. I often have band dreams and they're crazy. I'm often with John and just talking about something, and I come to get my Hofner bass, ready to play, and it's covered in sticky tape. You know, dreams."

McCartney then noted that his dreams about Lennon are "always good."

Colbert also brought up the fact that McCartney lost his mother when he was just 14. Paul explained how difficult it was for him until he got involved in playing music and met Lennon. He also noted that he and John shared a bond because Lennon's mother also died when he was a teenager.

Later in the show, McCartney revealed that he recently saw the new film "Yesterday," about a struggling musician who, after having an accident, wakes to a world in which he's the only person who knows The Beatles and their music. He then becomes famous by presenting their songs as his own.

McCartney revealed that he and his wife wanted to watch the movie with an audience, so they sneaked into the back row of a theater.

"It was a good way to see it," McCartney said, adding that he "thought it was a nice movie" and "a pretty good plug for me."