Christopher Nolan is one of the greatest filmmakers we have today. He has directed movies like 'Inception', 'Tenet', 'The Dark Knight', 'Dunkirk', and 'Insomnia' among others. His upcoming movie 'Oppenheimer' is creating a lot of buzz and it is all set to hit the screens on July 21. Ahead of its release, Nolan has been giving interviews. In one of those, he revealed that he doesn't use smartphones. Yes, you read it right!