Grocery stores use a system called FIFO (first in, first out) to rotate products with a limited shelf life so that they'll sell before they spoil. We should take a cue from businesses and save ourselves both frustration and money, and yet, many of us don't. There are probably expired products lurking in your pantry and medicine cabinet right now.
When you're spring cleaning your pantry, don't just pull everything out and put it back in. Actually check out those jars, cans and boxes. Pretty much everything has an expiration date. Whether something like pasta is still good past its date is up to you, but awareness is a good thing. You may be periodically cleaning out the fridge anyway, but sometimes we forget about the condiments. They have a longer shelf life most of the time due to ingredients like vinegar and those fantastic preservatives, but that life must come to an end at some point. When in doubt, throw it out. While you're at it, consider a new organizational system so you don't keep buying cinnamon because you can't find it and assume you're out.
The medicine cabinet and your other bathroom storage areas also need to be purged of old stuff. Expired medicine can be dangerous at worst and ineffective at best. Cosmetics don't have expiration dates, but liquid-based ones especially can harbor bacteria and should go in three to six months. If it looks or smells bad, let it go.