What is the origin of the idiom "as good as gold" and when to use it?

The idiom "as good as gold" originally meant "genuine" or "authentic," with the allusion to gold as a precious metal. It was used to describe the authenticity or reliability of something, and it dates back to the late 1600s. Over time, the meaning shifted to primarily describe well-behaved or obedient behavior, especially when referring to children or animals.

What is the origin of the idiom "good as gold" and when to use it?

The origin of the idiom "good as gold" is unclear. However, it likely stems from the association of gold with value, purity, and positivity. Gold is often used metaphorically to represent something valuable or precious, and in this case, it represents good health and a positive attitude. It is used to suggest that the person is in excellent physical condition or possesses a cheerful and optimistic attitude.