In the previous example, I put quotes around the capital letter O. Because, quite frankly, barewords are painful.
It's also important to look at it from the perspective of someone fixing the barewords but not fixing the real problem, as some may read the capital letter O and think it to be a zero (0) and brute force the solution by getting rid of the barewords by quoting everything.
So without warnings, there's no difference between a quoted letter O and a quoted number 0. If one is starting out with the language then hopefully I've pointed out some positives about strict and warning.
example with a quoted number zero
my $string = 'hello world';
sh-3.2$ perl absurd2.pl