If you want a hard one to explain - try the following. It is part of the history of a package that was shipped from Austin, TX to my Oregon location. It arrived two days after the final tracking information in this list.
February 19, 2017, 2:52 pm Departed USPS Facility MEDFORD, OR 97501
February 18, 2017, 3:23 pm Arrived at USPS Facility MEDFORD, OR 97501
February 18, 2017, 4:39 am Departed USPS Facility FEDERAL WAY, WA 98003
February 17, 2017, 3:10 pm Arrived at USPS Facility FEDERAL WAY, WA 98003
February 15, 2017, 2:40 pm Arrived at USPS Facility NORTH TEXAS PROCESSING AND DISTRIBUTION CENTER
February 15, 2017, 1:20 pm Departed USPS Facility DALLAS, TX 75398
February 14, 2017, 4:28 am Arrived at USPS Facility DALLAS, TX 75398
February 12, 2017, 10:45 am In Transit to Destination
February 11, 2017, 3:45 am Arrived at USPS Facility FEDERAL WAY, WA 98003
February 8, 2017, 7:58 am In Transit to Destination
February 7, 2017, 7:58 am Departed USPS Facility DALLAS, TX 75398
February 7, 2017, 7:31 am Arrived at USPS Facility DALLAS, TX 75398
February 4, 2017, 2:46 pm In Transit to Destination
February 3, 2017, 2:46 pm Departed USPS Facility FEDERAL WAY, WA 98003
February 2, 2017, 7:28 pm Arrived at USPS Facility FEDERAL WAY, WA 98003
January 31, 2017, 7:47 pm In Transit to Destination
January 30, 2017, 8:36 pm Departed USPS Facility AUSTIN, TX 78710
January 30, 2017, 7:47 pm Arrived at USPS Facility AUSTIN, TX 78710
There was some non-standard information - in addition to a perfectly proper address. Apparently this non-standard information threw that automated system into a tizzy and caused it to loop back and forth between Dallas, Texas and Federal Way, Washington. Eventually something kicked it out of the loop (perhaps my complaint about the package) and sent it for special handling at the North Texas Processing and Distribution Center.