Why exactly is Jon telling Garfield about the can opener? What is the implied message? "The can opener is broken... so I'm not going to feed you"? "... so dinner will be late"? "... can you help me with this can"? "The can opener is broken so I'm going to set the unopened can down in front of you and watch you walk away."
Garfield, despite a steady diet of human food, still considers cat food a vital part of his regimen. Now could be he likes it, could be his food addiction is so advanced it doesn't matter. They're all insightful, none so much as realizing that though he's confident walking around on hind legs, stands on the table to be at eyeline height with his peers, and has learned to operate devices like blowtorches, Garfield maintains vestigial traces of his animal roots. We get few glimpses to let us know if this is species pride, self-punishment, or a way to remember his roots, but today Garfield considers missing his sacramental meal "an emergency."
I generally roll my eyes at those wags who question comic strip joke-logic, but it's kind of funny that Garfield has managed to conceal an acetylene torch in the sparse environs of the Arbuckle house.
Q: Why not just keep a second can opener for emergencies?
A: "I have a second can opener" is not half the punchline as Garfield threatening to burn his master's face off for a mouthful of wet horsemeat.