The reason is simple , lexicals (my) are destroyed/destructored/cleanedup in-order

Where as, globals are cleaned up during "global destruction" before program exits but not in-order as there is no order they're globals

You can short-circuit cleanup with POSIX::exit() for even faster exit, but then destructors and stuff dont ...

Example

##  $stuff not exist
{  our $stuff = 1234; }
## $stuff still exist
{ my $lexi = 1234; }
## $lexi cleaned up here but $stuff still exists
{ my $flexi = 1234; } 
## $flexi cleanedup but stuff still exists
exit;
## $stuff cleaned up here in whatever fast order it happens to come fr
+om the perl memory stack
[download]

There are discussions on this just search for global destruction order, site:perlmonks.org global destruction order

see sub DESTROY: Strange ordering of object destruction (global destruction order not guaranteed, Re^3: when is destroy function called ( perl -d:Trace dalek ), Re^2: Perl Gtk2 - ->destroy() is Not Causing the Script to Exit

Why does Perl have this odd behavior during cleanup?

Heheh, its always funny when people (me too) say something is odd/weird ... almost as if they're trying to say I know stuff but this doesn't behave like it should (i used to think this but I know better now)... but what they really mean is always I don't know what should be happening, why is there a difference in what is happening, even if they don't think this is what they mean