You are being confused by list context vs. scalar context. Compare and contrast the version below.

my $test_line = 'Happy Birthday';
my ( $parse1, $parse2 ) = $test_line =~ /(Happy)(.*)/;
print "parse1 = $parse1\nparse2 = $parse2\n";
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The match in list context returns the matches. Excerpts from perlop:

m/PATTERN/msixpodualgc
       /PATTERN/msixpodualgc
               Searches a string for a pattern match, and in scalar co
+ntext
               returns true if it succeeds, false if it fails.  If no 
+string
               is specified via the "=~" or "!~" operator, the $_ stri
+ng is
               searched.  (The string specified with "=~" need not be 
+an
               lvalue--it may be the result of an expression evaluatio
+n, but
               remember the "=~" binds rather tightly.)  See also perl
+re.
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Matching in list context
               If the "/g" option is not used, "m//" in list context r
+eturns a
               list consisting of the subexpressions matched by the
               parentheses in the pattern, that is, ($1, $2, $3...).  
+(Note
               that here $1 etc. are also set, and that this differs f
+rom Perl
               4's behavior.)  When there are no parentheses in the pa
+ttern,
               the return value is the list "(1)" for success.  With o
+r
               without parentheses, an empty list is returned upon fai
+lure.
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