This is one of our brain's "shortcuts" that let us process more information using fewer resources than a mechanical brain would require. If we had to observe every bit of information individually before we could form a brain picture, we'd never be able to process it fast enough to drive and stuff.
According to the story, the cat is fine. I had wondered about the effects of riding in a non-pressurized, cold cargo hold, but since the owner was there during screening, I can assume this suitcase was a carryon.
That's one of the few I knew.