Originally Posted by
Paul56
I'm a Canadian residing legally in the Status.
I was never told to carry my "papers" with me for presentation
upon demand.
If I travel which I do regularly then I do have my "papers" for
presentation "upon demand".
Why does this remind me of old war films where the authoritative
figure shouts out "PAPERS!" at random checkpoints.

Actually, you are wrong - as a perm resident, you must carry your papers at all times... see, for example, pg 8 of
http://www.uscis.gov/files/nativedocuments/M-618.pdf