I think you've missed something.

1. This is somewhat more of a feature. If you want to extract all matches from a regex, you can do @a=/regex/g and get all the strings that match. If you want the count, you could do $a=()=/regex/g;.
2. From perlre:

   Perl defines the following zero-width assertions:
   \G - Match only at pos() (e.g. at the end-of-match position of prior m//g)

   In other words, if the regex starts with \G the match has to start at pos or the regex doesn't match.
3. m//g shouldn't reset in scalar context until it fails. Otherwise you couldn't do loops such as while ($string =~ /regex/g) { ...

Perl Idioms Explained - @ary = $str =~ m/(stuff)/g by tachyon should help with regexes in list context.

Hope this helps.