Not quite good enough for the poetry page, but it gets the job done:

my $obsession = 'Perlmonks!';
my @day;
while ($obsession) {
    push @day, $obsession;
    chop $obsession;
}
print length $_, "\n" for reverse @day;
[download]

... or actually combining this with what Rudif did maybe:

my $obsession = 'Perlmonks!';
my @day;
while ($obsession) {
    push @day, $obsession;
    chop $obsession;
    print scalar @day, "\n";
}
[download]

§ George Sherston