A Hard Day's Night director Richard Lester has admitted he was surprised that the film became such a success.
The filmmaker directed The Beatles in the black-and-white comedy in 1964, and it did well both critically and financially.
Asked if he ever dreamed he would still be talking about it 50 years later, he admitted: "I didn't expect to be asked to talk about it in 1965 because it wasn't that sort of film.
"When it came out, someone said it was the Citizen Kane of rock musicals, but we didn't plan it to be. We tried to do the best we could with four people and the way we put it together seemed the only way to make it work."
A Hard Day's Night 50th Anniversary Restoration is being released on DVD and Blu-ray, but although half a century has passed, Richard can recall making the movie "like it was yesterday".
"I can't remember anything else - I can vaguely remember my wife's name, but that's about it!" he joked.
"I think it's amazing that 50 years on, a film with an ephemeral subject has the audacity to turn up again."
Richard retired from making films more than 20 years ago and insisted there isn't a project that might have tempted him back.
He said: "I think that the way films are made, the change to digital was such that where I thought I had an edge, because I knew technically what I was doing, disappeared. There are a lot of things with digital filmmaking that I don't like very much, so I thought it was as good a time as any to stop.
"And physically I'm probably a lot better off having done so."
:: A Hard Day's Night 50th Anniversary Restoration is available on DVD and Blu-ray from July 21, courtesy of Second Sight Films (secondsightfilms.co.uk).