Why We Say 'Memento Mori'

You may have heard the phrase memento mori (remember your
death)—especially if you hang out with those strange Catholics—but
did you know there are three meanings woven into those two words?
Sure, the immediate thought that comes to mind may be the fact that
someday we will die; and this is good to remember because that day
could be any day, so we should live accordingly. What people may
not recognize, though, is that memento mori could also be a
reminder to the Christian that we have died to ourselves, so that
we may gain eternal life in Christ. As St. Paul says, “I have been
crucified with Christ; it is no longer I who live but Christ who
lives in me” (Galatians 2:20). The life you live is not your own.
Remember, as a Christian you have died to yourself. Entering your
day with that in mind may be difficult if you want to live for
yourself, but it could also be liberating if we give everything to
God. Thirdly, it is good to “remember your death” because it is a
reminder of the joy that will come when we live with Christ for
eternity. Remembering our death in that way can fill us with the
strongest kind of hope.