Well, it took two lumps over the head before I got it but now the required suite of uses on all code I write is:

use Data::Dumper;
use strict;
use warnings;
use perldiag;
[download]

But the beginning book I learned from was in Perl 4, and I assume that was why it did not have these uses as paramount. Come to think of it, very few books I own make a point of including these highly important standard modules.