I seek the title of a movie (as well as producer and date), whose opening scene had a voiceover in which the narrator says, "if you live long enough, at least one good novel will write itself". I vaguely remember the narrator adding some more words, "to live long enough, avoid getting mixed up in more than one war".

I seek the details of this movie and its writers, because at the time I saw it, the voiceover's premise seemed completely implausible... that a novel could write itself. Now, fifty years later, several plots for novels have emerged from my imagination and life experiences. And, the plots are are rather unique and original, not the usual tropes.

The movie's atmosphere, in clothing, architecture, and American speech, was evocative of early 20th century USA... like Disney's main-street theme park. The style of the movie "A River Runs Through It" is similar, but that movie was made in 1992, and focuses on learning to write, in a more deliberate, pedantic manner.

The movie seemed to be based on a Hemingway novel, possibly "Farewell to Arms" or "Big Two-Hearted River" or "The Sun Also Rises", although I do not remember any scenes of American expatriates, overseas. Unfortunately, I cannot find the thought expressed in that voiceover in any Hemingway novel, nor in a search of the net. I saw this movie on late night television, back in the late 1960s, or possibly as late as 1978. Possibly, the movie was only made for TV, or a TV series pilot.

I don't have many details about the movie, because at the time I saw the movie, it did not impress me as significant.

Can anyone recall? ...any movie with a theme that a novel will eventually write itself? ...mysteriously emerging from your life experiences?