A fired mistake cannot return to clay, but it can return as knowledge.

Some errors are irreversible in the material and still recoverable in the person. Once a thing has been through the kiln there is no unmaking it, though what you learned about thickness, timing and heat stays and shows up in everything you make afterwards. The object is lost and the lesson is not.

When something cannot be undone, write down exactly what you would do differently before the details fade. Then let the object be what it is. Salvaging the knowledge is usually the only salvage available, and it is worth more than it sounds.