Until I am measured I am not known, Yet how you miss me when I have flown. What Am I?

Answer: Time.

More Classic Riddles with answers

More Classic Riddles

Up and down,up and down, touching neither sky nor ground. What is it?
Used to threaten, used to defeat. Sometimes it grows, sometimes it shrinks. Used to conquer, used to protect. It marks your downfall, it marks your success. The true god of war, the creator of mess. What is it?
We capture light, and yet we don't. We reflect rays of sun, and yet we don't. Without us all the world is gray and dull for everyone. What are we?
What 5 letter word typed in all capital letters can be read the same upside down?
What 7 letter word is spelled the same way backwards and forwards?
What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?
What always was, yet I can never be?
What animal has no wings, but yet will fly?
What animal probably likes doors?
What animal would you get crossed a duck, a beaver, and an otter?
What biblical name is there which expresses a father calling his son by name, and his son replying?
What bird can be heard at mealtimes?