Dick Van Dyke Reveals Favorite ‘Mary Poppins’ Song and More from 1964 Classic (Exclusive)

Dick Van Dyke has nothing but fond memories of making Mary Poppins.

Speaking with PEOPLE in celebration of his 100th birthday and new book, 100 Rules for Living to 100, the actor opens up about his most famous role as the cockney chimney sweep.

Asked about his favorite song in the musical classic, Van Dyke shared, “I think the first number, when we go into the fantasy thing.”

Instinctively, he broke out into song as he sang, “Ain’t it a beautiful day? Day? Brighter the moment in May. I feel like I could fly.”

“There’s something about that and the dancer went with it, that was just fun,” he continued.

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Van Dyke had a great relationship with his costars on the film, which made the experience that much more memorable.

“[Matthew Garber,] this little guy, he was ordinary. Oftentimes we’d have to stand there while they lit and he would get bored and he used to bite me on the butt,” the actor laughs.

“He would give me a bite, but he was just playing. The little girl was sweet. And of course, the lady of all time, Julie Andrews,” he continued.

“My problem with Julie was I’m not really a singer, and Julie had not only had that beautiful soprano, [but] she sang just a little on top of the note, a little sharp. I don’t know how many takes I had to do in the pre-record. I finally got there, but it was hard.”

Of Andrews, he continued, “I don’t think we ever even had an argument. We just had a good time. Doing a musical is fun. I don’t care what you’re doing, it’s just fun. You never get tired of it.”

Van Dyke’s casting in the film was something of fate, when Walt Disney himself heard a comment the actor made in an interview.

“I said in an interview that I didn’t think there was enough quality kids’ entertainment. Well, Walt Disney heard it, called me up and put me in Mary Poppins. And he took me around. He had several offices with watercolor paintings of the various scenes, and then he had the boys play the score for me and I went home walking on air,” he recalls.

“I knew way before we started that we had a wonderful movie. There was something… everybody was kind of affected by it. We knew we had something really valuable, really good to do. So we all did our best and enjoyed as much as we could. I can’t think of one thing that actually went wrong.”

There was one gaffe from production that he’s never forgotten, sharing, “When we all have tea on the ceiling with Burt Edwin, they broke for lunch and forgot about me and left me hanging up there. And I had to yell for help.”

“God, that was fun,” he laughs.

100 Rules for Living to 100 is available now, wherever books are sold.