Top 5 intresting things about 

The Penrose stairs illusion is based on a drawing by M.C. Escher

As with all of Nolan's movies, inception was filmed without 2nd unit.

In Japan the movie is broadcasted on television with number of dream level displayed in the corner

The Main character cobb is the same nolan used for a lead in the first movie " The Following” in 1998.

The inception was originally written as horror movie.

This movie has best IMDB of 8.8/10

Inception earn 836.8 million US dollar on box office