I tell friends that one of the coolest things about Bitcoin is, even if you don't use them yourself, is that it makes people as questions about all currencies.  Yes in a land where we use silver coins, you can get tipped over in a boat and loose your silver in the bay.  People loose a small amount of silver all the time and the holders and users of silver will have their silver go up microscopically in value.  There is no Bitcoin conspiracy, it works like digital cash.  There is nothing new here. 

BTW Other questions that get asked:
Q: Is bitcoin backed by gold or silver certificates?
A: No and virtually no other currency you use is.  Backed currencies have a high storage cost.

Q: Didn't someone hack into someones computer and steal their bitcoins?
A: I worked at a large bank in their engineering department. We were aware that hackers from Russia and other places were initially successful in stealing millions of USD from Citibank and other big banks, but these banks hushed it up in the press.  Bitcoin lacks a good public relations department.

Q: Can't (or hasn't) someone use it for buying illegal things like drugs?
A: Over a billion dollars in USD is used every year for buying illegal things.  Drug dealers on the corner in the bad part of down don't take Bitcoins, only USD.