When we say goodbye we probably don’t think too much of the meaning there. After all, we will see the person in a few days, hours or weeks and afterward we will say goodbye again- won’t we? One time however when we say goodbye it will be for the last time but we probably wouldn’t realize it unless the other person was on a death bed or in a similar circumstance.
Lovers sometimes quarrel believe it or not. There exists a non-written rule that lovers agree to never go to bed angry or without that goodnight kiss. Just imagine if they don’t makeup and the next morning only one of the couple can wake up. When you’re a kid and are headed out the door did you ever rush past your mom or dad without a second thought? Of course, you did but would you do that if you thought for one moment that you would never have the chance again to give a kiss goodbye? When I am departing after seeing my adult children I manage to at least give them a hug, a kiss and say I love them. Sometimes they even say it back.
Someday they may even pause and think- I may never see dad again.
Someday, they won’t.