Why does the relative positioning of these code elements matter?

C:\test>type t-Moose.pl
#! perl -slw
use strict;

{
    package test;
    use Moose;
    has x => ( is => 'rw' );
    sub doit {
        my( $self ) = @_;
        print $self->{ x };
        print ${ $self->{ x } };
    }
}

our @c = 12345;
my $o = test->new( x => \$c[ 0 ] );
$o->doit;


C:\test>perl t-Moose.pl
SCALAR(0x229cd4)
12345
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Invert the ordering and:

C:\test>type t-Moose.pl
#! perl -slw
use strict;

our @c = 12345;
my $o = test->new( x => \$c[ 0 ] );
$o->doit;

{
    package test;
    use Moose;
    has x => ( is => 'rw' );
    sub doit {
        my( $self ) = @_;
        print $self->{ x };
        print ${ $self->{ x } };
    }
}


C:\test>perl t-Moose.pl
Use of uninitialized value in print at t-Moose.pl line 14.

Can't use an undefined value as a SCALAR reference at t-Moose.pl line 
+15.
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