I need no movies to know what autism is.) About movies, is Asperger-like behavior of De Niro's character Travis in Taxi Driver is explicitly described in the s

I need no movies to know what autism is.) About movies, is Asperger-like behavior of De Niro's character Travis in Taxi Driver is explicitly described in the screenplay or was a side-effect of a good acting?) And that Jean Reno as Leon, you know.