1. They are sometimes disgusting. Taste the lasagna before you commit to eating a large piece. Better yet, get a friend to taste-test it.
2. You can leave the lasagna out on your counter for a few days before it goes bad.
3. If you have completely lost your appetite (which often happens), you can freeze the lasagna. You should take the lasagna out within six months or it might get freezer burn. When lasagna has freezer burn, it tastes horrible.
4. Do not continue eating the lasagna if it tastes weird when you take it out of the freezer.
5. If the lasagna was delivered in a reusable glass dish, after consuming the lasagna, return the dish to its owner! Strangely enough, people will at times hold grudges about not having their dishes returned to them. However, this is usually not the case with tinfoil!