Archibasilica Sanctissimi Salvatoris et Sanctorum Iohannes Baptistae et Evangelistae in Laterano Omnium urbis et orbis ecclesiarum mater et caput
The Mother and Head of all the cities and churches of the world. If you asked the average Catholic what church holds this title most would probably guess the other Arch-basilica, St. Peter's. in fact it is The Arch-basilica of the Moly Holy Savior and Saints John the Baptist and [John] the Evangelist on the Lateran [Hill]. You see why most people just call it St. John Lateran.
It, not St. Peter's, is the Pope's Cathedral going back to the 4th Century. The fact that the pope lives at St. Peter's and most ceremonies are held at St. Peter's doesn't change it's status.
It is a reminder of how provincial we all are not only in geography but in time. It is our native tendency to think of "normal" as the way things are at the time and place we grow up. Everything else we look at as odd or, worse yet, wrong. Unless we make an effort, we lack a global and historical perspective that we need if we are going to really understand the meaning of the word Catholic.
How often do the idiosyncrasies of a particular pastor or period get enshrined in the word's "We've always done it this way"? Today we are challenged to remember the truly historic and universal nature of the church.