1. Jake didn't "realize" anything, it's just a cat. All Jake knows is that at some point it's owner stopped feeding it cheap takeout pizza and potato chips. Which means Jake is still alive. If Jake understands this on any level, Jake is Grateful.
2. And now Jake is wondering why there's this delicious-looking slab of salmon sitting there in the fridge, and he has to settle for this dry stuff. What the hell?