The next time you're scraping the dregs of your dinner into a Tupperware container, think about it this way: Would you shove wads of cash into the back of your refrigerator, never to be seen again? We think not. So why are you ignoring your leftovers? We know it's not as much fun as going to McDonald's or getting a deli sandwich, but just force yourself to reheat leftovers for lunch once in a while. Your bank account will thank you.