I come bearing a question about the crossing and the memory tolls themselves:
How fitting does a memory need to be to the prompt?

The most obvious choice I have for the skeleton here might be a larger toll than he'd willingly offer, so I think he's going to try something that sorta fits. Is there a chance of offered memories failing to be taken? If so, would the Ferryman give a gentle/sad nudge to try again with something else?