Cats are not the lazy, low-maintenance pets we humans think they are. Many people have told me they prefer cats (to dogs) because they can leave for the weekend and just leave food out. Cats prefer we stick to a strict schedule - especially for confined (indoor) cats when it comes to feeding time. They feel the most safe when you pick a time to feed and adhere to it - you have about a 15 minute window on either side of that time before many cats become fractious.
I see this with my cat and our foster; they are generally well adjusted to one another until I'm late with a meal, then they begin very rough play on the verge of fighting. This boils town to territory insecurity. In their eyes, their resources have become unpredictable and they no longer can rely on when the next meal will come.
For the best behaved cat, follow their orders! (Which starts with "feed me on a regimented regular schedule!")