Good Riddles

Question: When you fall in me your as happy as could be, but you fall into depression when you lose me.

What am I?

Question: If it takes three men two days to dig a hole, how long does it take one man to dig half of a hole?

Question: 5 bricks construct me, you'll find a candle in the middle. I am the antithesis of heavy, Without me you couldn't read the riddle. What am I?

Question: My name can have any letter of the alphabet, but I always have 2 X's.

What am I?

Question: A man goes rock climbing and falls. But at the end of the climb, he appears to be fine. What happened?