A walk

Question: A man goes down to the beach and starts walking on the beach, he has to get to the circus in a hurry and so he practices his act on the way, even though he had walked for an hour his feet weren't the least bit tired, why?

Question: People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?

Question: During what month do people sleep the least?

Question: When is 99 more than 100?

Question: What can be broken but never forgotten?

Question: What gets broken without being held?