What's your favorite RIDDLE in English?

Riddles (adivinanzas) in English can be tricky to solve, but they are a great way to practice the language.

If you don't know any in English, share one from your own language.

Here's mine:

"I am the outstretched fingers that seize hold of the wind, 

Wisdom flows from me in other hands,

Upon me sweet dreams are dreamt, 

My merest touch brings laughter"

(Let's see who guesses it first!)