The True Pain does not arise from loss or physical interactions. It is the realization of the Universal truth. The sudden disruption of flow made it rise to your attention, the attention is lost, and the vicious circle repeats. The flow will never be left alone, never at peace. But the realization is still achievable, without exposure to Pain.
The Flow is running throughout your life, sometimes fast, sometimes slow. It crops up rock and debris on it’s way. It is Every Changing, never the same shape or speed. Then suddenly, you allow the peaceful flow to stop. You have lost track of reality, It comes lurking. When the pain arises you realize, the hard way, the Universal truth. Impermanence.
You cannot alter what has happened. You hear of a horrible murderer, who has killed seven children. You mind runs wild with anger and emotion, anger towards the murderer and compassion towards the parents. You allow your emotions impair you of your own life and health. Of something that has already happened, and you took no part in. You, The World, The Universe is ever changing and unpredictable. You could not foretell the horrible event, or know what will happen next. You can only alter the present moment, become Mindful of yourself and your surroundings.
The True Pain is realizing this. That everything, despite the case or situation, is impermanent.