At this stage of his illustrious career, Paul McCartney has seen and done pretty much everything. Now that he's in his 70s, he's officially at an age when most artists start to think about slowing down. But Paul McCartney is not most artists.

"I can't imagine ever not doing it," McCartney told Rolling Stone during a recent Q&A session from the road, where he's traveling the world on his Out There tour. "It's what I do, and it's what I've always done, and I love it so much."

Not even the bass-playing former Beatle is immune to the ravages of time, however. "Of course, there's got to be some kind of physical limitation," McCartney admitted before quickly adding, "but I haven't found it. I mean, I did that show last night, and I'm thinking, 'Jesus, God, man. You know, you're not 25.' But then, my other side of my head's going, 'Yes, you are! Get on with it!' So I haven't found my physical limitation yet. If I do, then I'll have a think about the question. 'Til then, I'm ignoring it."

It helps that McCartney can afford to keep some pretty good company onstage. "We've got a really good band," he enthused. "We're very happy with the show, because we've honed it down over the years as to what we like playing and what we think the audience likes to hear. There's some stuff the audience doesn't even know -- not many, I must admit, but a few little ones. So the show just seems to run itself now. I'm constantly amazed at it, actually."