Food does not get moldy overnight.

I have a feeling someone was playing a trick on you.

How could you tell? Did the food actually have flavor?

I’m surprised the person didn’t knock on the door when it was delivered

I'm guessing OP meant "moldy" in a "gross and messy" sense, but since we're here: "Despite the fact that most posts about the insidious nature of McDonald’s food not decomposing were not altogether scientific, people believed them so intensely that, for a while, McDonald’s website even included a section in their FAQ about why their food “doesn’t rot.” But the truth is almost anything can avoid rotting under the right conditions, including human bodies. Therefore, next time you see one of these posts, you can chalk it up to the fact that people, in an attempt to scare others into not eating a food that is, admittedly, less than healthy, are really just making much ado about nuggets."