Garlic
You’ve certainly caught up with it by now, right? Never leave any garlic in the refrigerator. If you do, the garlic will just get rubbery, moldy, and would sprout. Looking at the garlic you left in the fridge, it will look pretty normal until you open it. Know for a fact that you don’t want to see or smell that thing.
Honey
The reason why this is on the list seems like a no-brainer. Honey is a naturally preserved food item, so if you leave it in the refrigerator, the process of natural sugar crystallization in honey is actually speeded up. It’s just going to give you dough-like honey, something that no one wants.