Nolan shared, “It’s not in the script, actually, which for me is very rare. It’s a sort of symbol, a symbolic representation that started to insert itself in the filming.”
He added, “I’m a very controlled and controlling filmmaker, and I don’t often shift something as important as that, but it was something that just kept pulling us in.”
Fans may have assumed the ending was another instance of Nolan’s penchant for parallel filmmaking, but it wasn’t until editing the film that the exact opening emerged.