Why use a complicated regular expression? 
my @section;
my $i = -1;
foreach (split /\n/, $str) {
    if (/^===Comments===$/) {
        ++$i;
        next;
    }
    next unless $i >= 0;
    $section[$i] .= "$_\n";
}

[download]
Now @section will contain all the text after ===Comments===, one chapter at a time.

In reply to Re: Regular Expressions Challenge by JavaFan
in thread Regular Expressions Challenge by danj35

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