Day 6... my least favorite part of the game.
Why?
Spoiler:The gemstone riddles. Not that I think copy protection is unfair somehow, or that the riddles are too hard (although they can be tricky). No, it's the fact that Robin has no reason to know the lore on which the black monks test him. And that shatters my suspension of disbelief.
On Day 7, Christy Marx makes a point to show how Robin learns the Hand Code and remembers it. It thus makes sense, from a story point of view, that he can use it later on effortlessly, even though the actual players have to go searching for their manuals.
But on Day 6, Robin is asked to identify the gemstones out of the blue. It's never shown that he knows the lore, but he would have to in order to survive.
The gemstone lore is probably not common knowledge; why else would the Fens Monks use it as a way to identify one of their own? I'd think they would want a foolproof code. So how does Robin know it?
On the other hand, Robin is more educated than the rest of the Merry Men (Little John, for example, can't read). So maybe he has stumbled across the ancient knowledge in a book somewhere, before he became an outlaw. Still, if Christy Marx made the effort to rationalize the Hand Code, I would've expected her also to explain why Robin knows the gems' properties.
Same goes for the Druid tree names. Robin knows the trees by sight, surely, since he's so well acquainted with the woods, but is he really that much of a scholar to be able to name them in another language? The lamp puzzle in KQ6 bothered me for the same reasons.
Of course, it's Christy Marx. And it's copy protection. Quality game design, normally her trademark, goes out the window when you add the latter to the former. 
(I counted the number of times I had to look something up in my manual on a recent playthrough--it was about 11, and that rises to 19 if you count selecting the 9 proper gemstones individually. Dial-a-Pirate was SO much easier, and kinder to the player.)
