A student might have to tell her friends she can not go with them to the movies because she has to hit the books.
Not hitting the books could lead to an unpleasant situation for a student. The father or mother may hit the ceiling when they see the low grades.
Someone who hits the ceiling, the top of the room, is violently angry.
A wife may hit the ceiling because her husband forgot their wedding anniversary.
To build something of wood, you usually need a hammer. That is what you use to hit nails into the pieces of wood to hold them together.
When you hit the nail on the head , exactly on its top, it goes into the wood perfectly.
And when someone says your words or actions hit the nail on the head, he means what you said or did was exactly right.
If you are tired after hitting all those nails on the head, then it is time to hit the hay .
That expression comes from the days when people slept on beds filled with dried grass or hay.
Some people slept on hay in barns where they kept their farm animals.
Hitting the hay simply means going to bed. That is a good idea. I think I will hit the hay now.
