99% of all questions on Perlmonks are from novice and intermediate programmers. As such, the concept of commenting difficult sections of code is alien to them. As this question deals with a counter-intuitive optimization, mentioning that commenting it well is a reply well-served for most people who ask questions here (and on #perl and on #cgiapp and ... etc).

I wholeheartedly apologize if my reply insulted you - it was not meant as such. Note - I didn't even notice that you weren't a native English speaker.