I Have Cleaned Since 1999 (I think?)

I have this pile of unopened mail on the table that I go through every week or two. It's stuff that seems fairly unimportant, probably junk mail, but I open it all just to make sure. As a rule, the oldest date in the pile is the day after the last time I cleaned. Today, however, I found this in the pile:

I did live in Pueblo in 1999. 

This is the kind of thing that makes me question the laws of physics, parallel universes, perhaps Cthulhu is real. If I have found the 1999 water report for Pueblo,  Colorado in my recent mail, anything is possible.