I absolutely hate "good-byes." There is a finality to them that doesn't ring true. Because we have immortal souls, we have the hope that partings are not forever, be it the loss of a loved one, moving away, or simply that your life passed through another's never to pass by theirs in this life again. After all a "good-bye" should really mean "farewell" and "godspeed" to express well wishes to the wayfarer on his journey, for as St Therese says, "the world is our ship and not our home."
This, while true, does not usually make the "good-byes" any easier. We may assent to this truth intellectually, but the heart is another matter. The loss that comes with a parting can be one of the most painful experiences a person has to go through. I think this is because it is an adjustment to life without a particular person or particular people in one's day-to-day, and this may carry such a heavy weight because of exactly that...the weight, the magnitude of that person's influence was such a presence to us.
I have a picture frame whose caption reads, "some memories we never forget because our lives are forever changed." In it is a photo of my uncle who I lost last year, who was one such person to me. It has taken me more than a year to realize the simple truth that he is more present to me now than he could have been on earth. When our lives are changed because of a particular person, it means that their presence will always be a part of who we are, and that is extraordinary.
Sometimes the unexpected "good-byes" are easier and sometimes they are harder. It doesn't seem to me that the preparation or lack thereof for that change makes it any easier. The strongest consolation for this comes in the Irish blessing: “May the road rise up to meet you; may the wind always be at your back; may the sun shine warm upon your face, and rains fall soft upon your fields, and until we meet again, may God hold you in the palm of His Hand.”
For the knowledge that you will meet those you love again fills your heart with anticipation rather than loss because there will come a time when there will be no more partings, no more "good-byes," no more farewells, but only joy in each other's presence within the Presence of One Who will "wipe away every tear."