Riddle

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

Choose an answer

A.Distance
B.Money
C.Speed
D.Time
Hint: It's a word with 4 letters, starting with "T".

Answer

Time

Why this is the answer

This classic riddle describes time -- it isn't fully appreciated until measured, and once it has passed, people often regret not using it well.

This riddle is filed under "What Am I?" Riddles and rated Medium.