WHY YOU SHOULD ALWAYS use strict

    #!/usr/bin/perl -w
    use strict;

This way, you'll be forced to declare all your variables with my() and also disallow accidental ``symbolic dereferencing''. Therefore if you'd done this:

    my $listref = [
        [ "fred", "barney", "pebbles", "bambam", "dino", ],
        [ "homer", "bart", "marge", "maggie", ],
        [ "george", "jane", "elroy", "judy", ],
    ];

    print $listref[2][2];

The compiler would immediately flag that as an error at compile time, because you were accidentally accessing @listref, an undeclared variable, and it would thereby remind you to write instead:

    print $listref->[2][2]