"[hit] the hay" の定義と意味

What is the origin of the idiom "hit the hay" and when to use it?

The idiom "hit the hay" has its origin in the practice of using hay as a common and simple material for making mattresses or bedding in rural areas during the 19th century. The expression captures the idea of going to sleep, often after a day of work or exhaustion, and resting on a bed made of hay. Over time, the phrase has been widely adopted to signify the act of going to sleep or retiring for the night.