[dufekin]

But I actually never lived at my parents’ current address and never submitted an order to forward my mail (or someone else’s mail) from there to anywhere else.

[muawiyah]

But you never lived at the house they're presently living in. On the other hand they moved there from somewhere else and you lived there, right?

The current automated system "catches up".

Years ago you'd see situations where someone moved more than once in a short period, or had moved with an individual order from a house where other people moved from later ~ you could end up with all sorts of yellow tags pasted all over a piece of mail reflecting all of that.

Today the computer system takes care of all that, then prints the information in invisible ink on the face (or back) of a letter.

Neat stuff eh?!

You were no doubt thinking there were human beings handling your mail.