He's almost about to ask if Papyrus can really taste that, but seems to realize that is likely one of those questions he's heard before and Will Henry doesn't want to make himself look stupid. He's rather careful about that, gets yelled at too often for minor gaps in his knowledge by the Doctor all the time.

"You just make them for fun? Not even to keep a secret door hidden?" That is the only kind of 'puzzle' he has encountered. There had been a puzzle lock hiding a secret entrance to the tunnels below the graveyard. That was how Warthrop's father had kept a den of monsters secret from the town. Well, at least until they had escaped after his death.