Famous Movie Lines That Were Actually Improvised
Taxi Driver
Think of a classic line from Taxi Driver. Or from all movies, for that matter. Chances are, you thought of the infamous line from Taxi Driver where Robert De Niro says, “You talkin’ to me?” with typical New York bravado.
Well, the script doesn’t include that line, only saying that “Bickle speaks to himself in the mirror.”

Taxi Driver
The rest was all De Niro, baby. He improvised the whole thing and Martin Scorsese preserved it as film history.