Am I the only one who didn't realize that when I first saw the card?
Wrong. This is not the case when you've drawn your deck.
[/edgecase]
Also, there may be a card in Guilds like:
Awesome silver
Treasure - 4
Worth 2$
---
When you reveal or discard this (other than during your clean-up phase), put it into your hand.
Alternatively there could be a Guilds card that is a downgraded but somewhat DA-friendly gold.
Fragile Cargo
Treasure-5
worth 3$
---
When you reveal or discard this (other than during your clean-up phase), trash it.
[edit] That's still too strong for a 5-cost gold. There would need to be some additional limitation that applies regardless of the kingdom, like an inability to purchase treasure cards or something else that is not at all like Quarry.
As it stands now though, if you guessed incorrectly with a Mystic, the top card that was revealed is still on top and so you now know for certain what the top card is(at least you do if you were paying attention of you have the goko log). What you do after that is up to you.
It's kinda cool that Mystic can get its extra benefit from a few cards that Wishing Well can't get its extra benefit from such as Lookout, or possibly Spy and Iron Monger.