I don't quite recall what I did but on my first ever play through of final fantasy 7 I messed up in a way that would never allow me to breed chocoboos, or at least getting the one that allows you to get to the island where you can get knights of the round. I've finished the game without ever knowing what that summon looked like and it annoyed me greatly. I've replayed it years later and used guides to make sure I wouldn't miss out this time