2. I spend entirely too much time at the office
Or maybe a third:
3. The mail carrier recognizes the New Leaf name and knows where NL is, not just me.
No matter which, I'm still agog that the mail carrier didn't just send this back with "what the HECK! Have you sent a package before today??"
(for the record, I think it's #3, but it was hilarioius thinking it was #1!)