Perl can be very opaque unless use strict; use warnings; is used in every module.

Make very sure that you firmly understand how sessions are supposed to work... that is to say, in any language. And mind you, I don't mean that disrespectfully to you:   I never really felt that I understood it myself for quite some time. Frustration, on top of everything, definitely clouds your vision because “the pressure's on.” (Raise of hands, please? Uh huh. Hold 'em up there... See?)