Seen on perl5-porters:

...and thus providing a rationale for C<exists $foo[5]>, as opposed to C<defined $foo[5]> which is merely checking for an array element containing a perfectly valid scalar value...

Exacerbating the number of ways you can count the disparate but indistinguishable sets of angels dancing on the head of a pin serves no legitimate purpose save to further elevate the priesthood of the triviamasters above neophyte and acolyte alike by needlessly injecting the abstruse into the quotidian, thereby reducing the already debatable accessibility of Perl by those common masses who need it most--all because of the irrepressible urge by the destructively clever to continue unfettered these labyrinthine embellishments, gratuitous nuances of surpassing subletly and dubious utility. Let your true be true and your false be false, and add not to the already confusing number of falsehoods, lest the resulting eminently confusable shadings be forever beyond the ken of mortal men trying to get their jobs done without first subjecting themselves to decades of monastic study. --tom