Every weekday morning my husband and I listen to Garrison Keillor's Writer's Almanac on NPR. Keillor mentions writers whose birthdays it is that day, and talks about their work. This morning it was Frank Herbert's birthday. Herbert's magnum opus is, of course, Dune, winner of both the Hugo and the Nebula (the very first Nebula, in fact) and still selling well decades after it was published. It mixes ecology, Macheavelian politics, Zen philosophy, and detailed world-building into an unforgettable saga.
Keillor said that Dune grew out of Herbert's work on ecology, and was rejected by 23 publishers; Wikipedia says 20. Either way, a lot of editors were kicking themselves later. Herbert eventually got the novel published by Chilton's, the folks who publish car repair manuals.
So, yet another example of persistence paying off. If Herbert had given up after publisher 19, who would have heard of him—or Dune—today?
To quote Keillor's signature sign-off: "Be well, do good work, and keep in touch®"