Photo: George Burns/Harpo Studios

It's been 40 years since Love Story debuted and Ali uttered the immortal words: "Love means never having to say you're sorry." Over the past four decades, people have been moved—and baffled—by this line.

Ali: What does that mean, by the way?

Oprah: I was just going ask you! What does that mean? At the time I was in the 11th grade when I went to see that for the first time, and I was thinking: "God, love means never having to say you're sorry? Really, does it?"

Watch Ryan O'Neal talk about this infamous movie line.

Ali: You know, a really great actor would have said: "Excuse me, what does this mean? I can't say it." And there would have been two or three hours of rewriting this moment. It makes no sense, and I apologize.

Oprah: I'm so happy to hear you say that. It makes no sense!

Test your knowledge of memorable movie quotes!