A guy walks into a nut shop and asks how much is a lb of peanuts? The guy behind the counter says $7.55 a lb. So the customer then asks, how much are your walnuts per lb? The clerk says $10.59 a lb. So the customer says...what is that sticking out between your eyes, is that your d&ck? The clerk says, "Ah no, that's my nose. Why did you ask if it was my d&ck?" The customer say, well I thought it must be, as your nuts are so high.
As it's been explain to me...it's like buying a lotto ticket (or several) with the ability to get 80% of your money back if you don't want wait any longer. Plus it's offers free dreams!
I recently asked my economics professor the same question and he said it's the economic prospects for a country that determine the future value of its currency, not the price it trades at now or the price it traded at in the past.