If we are all going to depart one day, then what is all this mourning and suffering for? What you feel is not mourning, it is fear. Fear!
Life is but a wait for death. We will all see the seas, the stars, the trees, and the so and so. We will taste many things. And then we will inevitably sing the “Farewell, I'm leaving” song.
Then, may both the ones who leave and the ones who stay be at peace.