3:50 "options are the right but not obligation to buy or sell"<br /> who on earth is so stupid to take part in such a gamble?<br /> this is just another intelligence test, exploiting the fact that most people are idiots.

If language originally evolved as a tool of preservation, its roots are naturally based in self-interest for purposes of survival. That hasn't changed, we still rely on language and its conventions for survival. The point being, that we tend to forget that definitions and conventions are based in, derived from, arbitrary inventions.