Well, it won't print 'Anything goes' for 2 reasons: the dereferencing is incorrect, and the value does not hold 'Anything goes' :-)

my(@arr);
{
    my %var;
    $var{"love"}="Anthing goes";
    $arr[0]=\%var;
}
print ${$arr[0]}{love},"\n";
print $arr[0]->{love},"\n";
print $arr[0]{love},"\n";
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But, indeed the hash still exists in memory as long as something points to it (it isn't let go until its refcount hits 0) --- this is commonly used for constructing a datastructure within a subroutine and returning a reference to it ... think of OO and returning a blessed reference from the constructor for example.