On Wednesday, we commemorate All Souls' Day, remembering all who have died. It would be most appropriate to visit a cemetery if possible, to offer a prayer for our dearly departed, and to pray for them. We do not have certainty of their current state - heaven united with God, condemnation because of their rejection of Him, or in the state of purification (Purgatory) where they are purged from the attachments to sin, having been forgive of them already. Because of this, this day offers us the reminder to pray for them.
But these days are also a gentle reminder to us to remember and prepare for our own death. As an epitaph on a grave stone puts it, "Remember me as you pass by, As you are now, so once was I, As I am now, so you must be, Prepare for death and follow me." Put more succinctly: Remember death - Momento mori.