In the node you mention, the author was skipping over comments in the configuration file, not the code.

The Perl interpreter doesn't run through the text of your program directly, but compiles it into an intermediary byte-code representation, which is then executed. Comments are not present in any form in this representation, and thus have zero effect on the speed at which your code is run.

And unless you write epic novels to describe your subroutines, they have utterly negligable impact on your compilation speed as well :-)

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print