Why do the boys think the island is a paradise?

The boys think the island is paradise because there are no
adults with them and therefore, they are free to do what they want, when they want;
there is no one to hold them accountable or responsible. This is evident when, despite
crashing onto a deserted island, the boys' actions are quite carefree.  "Ralph danced
out into the hot air of the beach and then returned as a fighter-plane, with wings swept
back and machine-gunned Piggy" (11).  They do not seem to realize the perils that may be
ahead and have a hard time focusing on important matters, such as the signal fire, which
they let go out.  When Piggy tries to speak about building shelters, "all the boys
except Piggy started to giggle; presently they were shrieking with laughter" (45).  The
island becomes a playground for them as some boys build sand castles and others become
"explorers."  Unfortunately, they will learn that their paradise is
short-lived.