First step of a photographic project about remember that you have to die.
Memento mori is a latin expression, originating from a practice common in Rome. As a general came back victorious from a battle, and during his parade received compliments and honors from the crowd of citizens, he ran the risk of falling victim to haughtiness and delusions of grandeur; to avoid it, a slave stationed behind him would say "Respice post te. Hominem te memento" ("Look after you [to the time after your death] and remember you're [only] a man").
In art, mementos mori are artistic or symbolic reminders of mortality. In the European Christian art context, "the expression... developed with the growth of Christianity, which emphasized Heaven, Hell, and salvation of the soul in the afterlife." It names a genre of artistic creations that vary widely from one another, but which all share the same purpose, which is to remind people of their own mortality. So, remember, you are too mortal.