Werner Herzog’s Fitzcarraldo was inspired by Carlos Fitzgerald, a rubber baron operating in Peru who exploited Native populations. (He was called “Fitzcarraldo” because it was easier for locals to pronounce.) For the movie, Herzog changed his name to Brian Fitzgerald and made him a much more sympathetic opera lover who just wants money to fund his opera house.
Another key change: OG Fitzcarraldo disassembled a 30-ton boat to cross the space between two rivers. Herzog was like, “What if the boat was 300 tons… and we pulled it up a mountain?” Like, no special effects. An actual heavy vehicle not built to be going over mountains. (The boat is still rusting away in a Peruvian jungle to this very day.)
He also hired some native populations for the film, some people got injured, some died, and it made for a pretty tidy point of comparison that Herzog himself had truly become Fitzcarraldo.
Still… kinda gotta agree with noted movie critic Nelson Muntz.