After hearing during a radio newscast this morning, "You'll have to pay to park at (a particular casino and amphitheater)," I growled.
Immediately, I thought, "Why did I react that way? I don't go to casinos, so I've never been to that venue and will never go there. This doesn't affect me."
The principle of it explains my reflexive growling, I think. Why wouldn't the thought of an irritating, mundane expense elicit a growl?