Old School is gold
First Blood (1982) was adapted from writer David Morrell’s 1972 novel of the same name. Morrell named the character “Rambo” after a type of apple cultivated by a 17th-century Swedish settler named Peter Gunnarson Rambo. In the book the character didn’t have a first name, but in the movie he was given the full name John Rambo.
While writing the book, the author was struggling with what to name his main character when one day he had an apple as a snack. According to Morrell, “I took a bite of the apple and discovered that it was in fact delicious. ‘What's it called?’ I asked [my wife]. ‘Rambo,’ she replied … Instantly, I recognized the sound of force. It also reminded me of the way some people pronounce the name of a French poet I'd been studying, Rimbaud, whose most famous work is ‘A Season In Hell,’ which I felt was an apt metaphor for the prisoner-of-war experiences that I imagined Rambo suffering.”