A Chain of disappointments

Lately the greenback is depreciating as optimism is spurred around the market. But anyone who trades against the greenback most remember that a depression is built on a chain of disappointments rather than the opposite. Maybe that whole optimism and anti dollar rally is just a big honey trap?
If the feds intention to print a large sum of money is the concern take a look at Japan. They have a history of printing large sums of money and the Yen has preformed rather well, why then this should affect the greenback?

*Please acknowledge that this is my opinion alone and is not a trade or an investment recommendation in any sort or way.