Many people write annual family letters as well.
Though I don't send mine (we live too boring a life),
I receive about 15 every year. So I not only have
my record of the year and the Holidays, but the
records of other friends and family.
All in all, I'd say it would be VERY easy to figure
out where Mr. Karr was on Christmas '96.
BTW I just caught your tagline. That's one of my most favorite scriptures.