The dollar. This has got to be the biggest wild card of all time. As a huge debtor nation it is in the US interest to have a weak dollar (to ease debt payments). The huge recent printing of dollars should be knocking USD down. However, every other fiat currency in the world is also printing money like mad, and USD is seen as the best of all the horrible fiat currencies, so it has gone up instead of down. Rising USD has limited the rise of gold in US terms. In other fiat currencies, gold is going through the roof. If/when the world reduces its faith in the USD, it should come crashing down, shooting gold through the roof in USD terms. That means gold will buy more dollars, but those dollars will buy less.

When I try to understand where gold is going, it gives me a headache.

When I try to understand where USD is going, it give me a nervous breakdown. In the end there are a dozen reasons for USD to go up (devaluing gold) and a dozen reasons for it to go down (valuing gold). Aaaaah!