I had a long train of questions inspired by the last line of the above node, ending with:

# When will they ever learn?
print scalar answer_when(\&learned_the_lesson);

sub answer_when {
  my $test_question = shift;
  for (my $t = 0; 1; $t++) {
    return localtime($t) if $test_question->($t);
  }
}

sub learned_the_lesson { 0 }
[download]

I will let you know when I get an answer.