Paul McCartney confesses: 'I have to relearn everything' before performing smash hits

According to Paul McCartney, there's nothing like writing songs — even though he may not remember how all of them go.

The Beatles icon told Al Roker on the "Today" show how he keeps track of all his hits and what's kept him in music all these years.

The 77-year-old admitted that when you've written as many songs as he has it's impossible to remember them all.

"Is it true that sometimes you have to relearn the older stuff?" Roker asked.

"Yeah, I have to relearn everything," McCartney said. "I've written an awful lot, so you can't retain them all. We go into rehearsal, and I learn them. 'Oh yeah, that's how it goes.' "

McCartney added his own songs often surprise him.

"Sometimes when you're relearning them, do you kind of look and go, 'You know, this is pretty good?' " Roker wondered.

"I do," McCartney said. "I really do, you know. That's one of the joys of doing some of the old songs. And you say, 'Oh, that's clever. I wouldn't have done that.' "

McCartney, who co-wrote dozens of Beatles hits, said he's discovered a passion for a different kind of writing as well: children's books.

McCartney coauthored the 2005 children's adventure novel "High In the Clouds," and his children's picture-book "Hey Grandude!" will be published in September.

McCartney told Roker he discovered this passion through his grandchildren.

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"As my kids and the grand-kids were growing up, I always loved reading to them at bedtime," he said. "I just loved being part of that experience, so I said 'It'd be nice to have a book.'"

After all these years, McCartney said one thing keeps him performing: his adoring fans.

"I think just as you come on, and it's like, 'Wow, they like me.' And it's a thrill. It's a big thrill."

McCartney gave one of his audiences a thrill earlier this month by bringing out his former Beatles band-mate Ringo Starr on the final night of his North American tour at Dodger Stadium in Los Angeles.

More: 'I love you, man': Paul McCartney brings out Ringo Starr for a tour-closing Beatles reunion

McCartney told Roker the enthusiasm for his reunion with Starr is stunning.

"It's really exciting to think that that still works. We thought we had five, 10 years maximum," he said of The Beatles. "We were a little rock n' roll group from Liverpool, and that was beyond the expectations. But then five years came. Ten years came, and we were still rockin'. And then it just kind of kept going. It self-perpetuated."

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Toward the end of the interview, Roker asked a question on many fans' minds: Will there be new McCartney songs in the future?

"Hopefully," he replied. "I've gotta think of it first. I'm thinking right now."

More: 20 essential Paul McCartney tracks that prove he's the best of The Beatles

This article originally appeared on USA TODAY: Beatles' Paul McCartney forgets his own songs, talks Ringo Starr