Used to command someone to be careful with a precious resource, especially to prevent their talents, positive traits, or advantages of any kind from going to waste or turning into something negative. We are all given a certain amount of butter for our bread, and the more we have, the harder it can be to secure. All it takes is one moment of carelessness, and that butter
may slip off the bread and into the
toaster as we are trying to use its residual heat to warm the butter to an optimal temperature in the post-toasting phase of
toast preparation. The next thing we know, the
toaster is giving off a noxious scent of burnt butter as a lingering reminder of the mistake we have made.