If you're encountering patches that seem to require an in-depth knowledge of
the more arcane parts of Perl, you've got a few options to avoid being bogged
down:
 
1) Ignore it, document it as needing to be done in the TODO file, and keep
   moving.
 
2) Use the tool at http://public.activestate.com/cgi-bin/perlbrowse to
   look up the patch.  This can often be very enlightening.
 
3) Hop onto #p5p on irc.perl.org.  You've got a good chance of finding the
   person who wrote the original patch there, or someone who intimately
   knows what it does.  They're friendly, and are expecting perl589delta
   volunteers.
 
If you're taking the "light" approach of simply picking out low-hanging fruit,
documenting them, and removing the completed sections from the split files,
then keep doing what you're doing.  However you're welcome to try the above
methods if you want to clear out some of those more tricky changes.