Time heals everything or does it?

There is a saying that Time heals everything and indeed it does but does it really. With the passage of time, the pain can be lessened but not entirely forgotten and any type of event can trigger repressed memories or pain and you are back to square one. I am saying that when somebody recovers from a traumatic experience, he/she can go on living but any event even remotely related to that experience can bring back harsh or painful memories. But there are some events where time will never heal how you feel. I am talking about loss of my father which I remember every day and the pain of which increases every time I hear about people living longer than what my father lived. Also seeing older people enjoying their dads bring back memories. The other big event that time does not heal is the loss of a child. You can say whatever about moving on but ask somebody who has loss their child in any kind of event before their natural life and you will see that time has not healed anything in their lives. This I believe is the most devastating event that a person has to go through and the time factor does not heal the loss of memories left behind by that child. You cannot just move on when one loses their child, because the pain it causes can only be felt by that child's parents and to a lesser extent the extended family and any event involving a child brings back your own aspirations about what the child was supposed to be at that age. There can be other events in ones lives which can be uniquely to that person and in their cases time will never heal what they have lost.