alt Hacker NewsWhy would the cat being comfortable make it sit on a mat?
Many sentences require you to have some knowledge of the world to process. In this case, you need to have the knowledge that "being comfortable dictates where you sit" doesn't happen nearly as often as "where you sit dictates your comfort."
Even for humans NLP is probabilistic, which is why we still often get it wrong. Or at least I know that I do.
Ah, but cats won't just comfortably sit on a mat if they feel there is danger. They will only sit on a mat if they feel comfortable! Absent larger context, the sentence is in fact ambiguous (though I agree your reading is the most natural and obvious one).