20 Things You Didn't Know About Inception

Do you ever wonder what that song is that they play to cue the team as they need to get ready to synchronize kicks? That song is Non, je ne regrette rien by Édith Piaf.

It's played multiple times throughout the movie, and it's more or less the film's theme song.

Interestingly, not only is the song prominently featured in the movie, but it's also subtly referenced in the most unexpected way.

Piaf's original recording was 2 minutes and 28 seconds long. Inception is 2 hours and 28 minutes long.

Granted, this could just be a coincidence, but it's just as likely that this was deliberately done by Nolan, even if only once the film was in post-production.