There's only one time Nolan has opened up about the endings to one of his films.
Christopher Nolan has garnered a reputation for ending his films with mind-boggling twists.
The one that still seems to perplex people the most is 2010's "Inception."
If you haven't seen the film, there are spoilers ahead.
At the end of "Inception," Dom Cobb (Leonardo DiCaprio) finally returns home to his kids after spending a long time in the dream world. Cobb carries a little top with him. If the top keeps spinning, that means he is in a dream. If it stops and falls over, that means he is back in reality. The final shot shows the top spinning, but it never reveals whether it falls over.
Five years after "Inception" was released in theaters and became a box-office smash, this one question still drives fans crazy.
At a recent Q&A at the Tribeca Film Festival, one audience member asked the director to explain what the ending of "Inception" means.
Nolan, who looked like he had heard this question just a few too many times, wouldn't explain the ending, but instead explained why he won't comment on it or the endings to any of his films for that matter.
He told a story about when his mind-bender "Memento" premiered at the Venice Film Festival in 2000.
"We got a very, very excited reaction to it," Nolan said. "Somebody had asked about my interpretation of the ending and I said 'Well, it's all up to the audience but this is what it means to me,' and I gave them in great detail what exactly the ambiguities of the film meant to me," Nolan said.
The press conference was never recorded, so his "Memento" explanation never got out. However, Jonathan Nolan, Christopher's brother, who wrote the short story on which "Memento" was based, advised him against ever explaining the ending of one of his films again.
According to Nolan, his brother told him, "You don't understand, nobody hears that first bit where you say it's really up to the viewers if you then give your interpretation."
"It's the last time I ever opened my mouth," Nolan said.
Christopher Nolan isn't the first filmmaker to be questioned about the ending of something he made years ago. He's in good company with the likes of David Chase, the creator of "The Sopranos," who recently gave an in-depth analysis of the show's ending following nearly 10 years of constant debate and controversy.
Nolan is known for his secrecy, so it is unlikely that we will ever get an explanation like that for "Inception" or his other films.
While he will never offer us a definitive answer (an interview in Wired is the closest he's gotten to giving one), we seem to have his permission to continue arguing over whether or not that top kept spinning.