I disagree about skyrimendtherapture said:snip
when given a quest most ncp's are basically saying "retrieve X that is in that one of the countless crypts/cave fill with draugr/bandits in skyrim. Since I assume your mind reader; I won't have give any hints or directions for the location of X"
If your lucky you might randomly stumble upon X at point less then 10 hours(in real time) later when not using quest markers. Maybe X is a cave/crypt you cleared in the past and you will mostly likely will never randomly stumble upon it.
X=fetch quest item