The Truth About Martin Scorsese And Robert De Niro's Friendship

Although the legendary movie-making duo initially met when they were both 16 years old, they didn't cross paths again until the 1970s, according to Metro. 

Just picture it: The year is 1973, and Martin Scorsese has already solidified his insider status with the "Movie Brats" — a term used to describe a group of the most influential movie directors of the 1970s (which included the likes of Steven Spielberg and Francis Ford Coppola), per Empire Online. Scorsese had only put one major film out and was working on his second ("Mean Streets") when he cast a young Robert De Niro as one of the leads alongside Harvey Keitel. 

Scorsese said of De Niro's acting in "Mean Streets" (which is now considered by BBC to be one of the greatest American films of all time) that he just "got the people, and the tone and flavor and temperature of it," and by the time they worked together on "Taxi Driver" just a few years later, he knew that "it was something extraordinarily special" (per Deadline).