Idiom of the week: To take the gilt off the gingerbread

Our idiom today is also related to Christmas: what does it mean to take the gilt off the gingerbread?

As you know, gingerbread is a spiced cake or biscuit. It's usually cut into a human shape -hence the gingerbread man you've probably seen in books and films. Back in the Middle Ages and Elizabethan times, these biscuits were covered with gilt (a gold coating) which could be real or -more frequently- artificial. 

What happens when you scratch away the surface of something showy? You're depriving it from its beauty, spoiling something that seemed truly valuable -and probably discovering its true (and more modest) nature. You're taking the gilt off the gingerbread.

Be careful with the misspelling 'take the guilt off the gingerbread'. The cookie might look like a little human, but it has committed no crime other than tasting heavenly.