There are many foods which people say taste better as leftovers. Now I don't know if it is all in the head, or if is scientific....like allowing more time for bacteria to creep in, but still if people like leftovers so much, why don't they make leftovers?
Seriously. Make a lasagna, wrap it up in tin foil, and throw it in the fridge. Wait a few days, and then heat it up. Yum! Much better!
I think they should even go so far as to start packaging leftovers marketing them. They can even make it look like its already been eaten and remove some of the pieces. Then it would be authentic.