The moon!

Every night when the sun goes down,
the moon comes up.
Well not every night.
There are nights when the moon doesn't show up.
But there is never a day that the sun doesn't come up.
There are days as well when sometimes one can see the moon.
Why is this so?
Why does this happen?
Despite being in the same sky,
why is the moon allowed to come together with the sun,
but the sun is never seen in the night.
The universe confuses us every time.
The universe!