Well, besides cockroaches and other creepie-crawlies, I would wager that the condiments in my refrigerator have a good chance, too. I pulled this jar out of the fridge at work:
This is a jar of muffalata mustard, made by me in 2001. Every once in a while, I rummage around for mustard for a sandwich, take it out, look at it, say "nah, " put it back in, and use something else. No, it hasn't been at work since 2001. And, to credit my co-workers, we do clean the fridge. I have commandeered the left produce drawer for myself and they leave it to me to maintain cleanliness. And it is clean, it just happens to have some pretty old inhabitants.
As I was slathering it all over a couple of slices of bread (no use being timid with it), my boss walked in and asked what I was putting on my sandwich. Strategically positioning the label screaming "I AM EIGHT YEARS OLD" away from her so she couldn't see, I told her what is was. Fortunately, she immediately got caught up in a reverie about the time when she and her husband made muffalata sandwiches for another co-worker's wedding shower.
So, how did it taste? It made a damn fine turkey sandwich.
And I put it back in the drawer ;)