In 1974, relative unknowns Henry Winkler and Sylvester Stallone appeared together in a film written by Stallone called The Lords of the Flatbush. Here’s a picture of the stars:

The interesting thing is that right after “Lords,” Winkler tried out for “Happy Days,” where in his audition he was basically doing an impression of Stallone’s character in “Lords.” Thus, Fonzie’s accent. Ever since I found this out, I can’t stop thinking about how much Fonzie’s “aaayyyyy” sounds like Stallone.