Answer:
When one does not know what it is, then it is something; but when one knows what it is, then it is nothing.
What has to be broken before you can use it?
4 rubber ducks were floating in the bathtub, 2 floated away and 2 drowned. How many ducks are still alive?
What superhero is terrible at their job because they always get lost and are late?
Taking this from a baby is said to be quite easy.
What is always coming but never arrives?