I guess that also explains why I can put 'our $var;' in package BB and have this version of $var carried through main. Each use of 'our' replaces any previous alias for the remainder of the execution. I'll have to re-train my brain on what to expect from packages :)
Makes me a little nervous that Perl would allow this without some kind of warning. Also makes me wonder what kind of problems could be made easier using 'our' in this way?