I'm not sure which is worse: knowing that you've lost your passport or driver's license or knowing that someone else lost it for you.
I'm voting for the second. In the first case, you know whom to blame, you know most of the story ("I remember I had it out of my wallet when I checked into the hotel ...") and you have some hope of finding it by retracing your steps.
But finding a passport or driver's license that is lost between its origination and your mailbox at your home is its own special kind of hell.
Here's your anti-Hades guide to resolving a lost-in-transit passport or driver's license.