I found out last year that our local Publix was selling "fresh" fish that sometimes stayed in the case for a week. They get shipments only on Tuesday, but don't put that fish out until the previous shipment has been sold. This explains the "fishy" smell.
Then yesterday, I found there was no ground sirloin on the shelf, asked the meat guy to get some for me, and instead of grinding some beef, he pulled out a slab of ground meat and had the machine slice and package it. When I asked him about this (because dummy me assumed that when I was buying ground beef in the meat department that I was getting meat fresh from the store), he told me that they get tubes of ground beef.
I always thought I was protecting myself from buying meat from a "processor" when I bought at Publix. Turns out I'm not. Be aware, people!