@Tfmonkey Halsey is mostly correct. “The die is cast” as in a fabrication shop - a die is a mold for casting molten metal. Usually a hollow material made from sand and is a one time use mold as you have to “break the mold” to remove the cooled molten metal. Not to be confused w gambling Dice ie throwing dice.

I wrote this right before the “I told you so” came up” so egg on my face

Also this might be a good time to update the “I told you so dance”