On the general subject:

Sometimes it's genuine curiousity and/or some weird impulse of the
player(s).  But sometimes, as you acknowledge, it's a common streak of
perverse (no, not that way) glee and amusement to force the game master
to do even more work, to improvise, and/or to see if they can "beat" the
GM's ability to do so.  If they can derail the GM's plans, go far enough
off the map, and/or force the GM to call a break to come up with
something, they've scored a point in the meta game.

"I stumped you.  I thought of something you didn't, went somewhere you
didn't anticipate.  That makes me more clever than you."

--
---------------
Kelly St. Clair
xxxxxx@efn.org