props has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks, I know a lexical resides in its enclosed block, this is a definite closure
my $total_size =0; find{ sub $total_size += -s if -f}, '.'); print $total_size, "\n";
why this is not a closure though ?
use warnings; use strict; { my $a; } $a=1 print $a;
in my eyes my $a is visible outside the {} many thanks