in reply to Re^4: 'our' is not 'my'
in thread 'our' is not 'my'

The point is that Perl is willing to trust you. Your telling it our $var means “I and all my friends in this lexical scope want to use this variable without qualification” (that's why it's the first person plural!). Since it believes that you know what you're doing, it doesn't want to warn you later when you do just what you said that you were going to do.