The crossover between the psychological and spiritual integration of suffering a loss
The object of one’s mourning is an imprint in the subject’s mind - memories of the person that they lost, whether through divorce, death, emigration or whatever. In some cases Freudian therapists may call some of the internalising ‘hallucinatory wishful psychosis’ i.e. 'hearing the voice of a loved one'. Whenever the word psychosis pops up in the psychoanalytic world, I believe there is a philosophical or spiritual understanding to be drawn, rather than a label of mental illness and non-understanding.
The Philosophical Bit
However you have experienced the loss of a loved one, whether through death, a break-up, a pet running away, leaving a job or community there remains a constant. That is the memory etched into your mind - the object of the lost one and what they meant to you.
They were an embodiment of something you loved, but it was you that loved them, the object that was loved was perceived in your mind and while their embodiment was the original source of this object, you now hold that object, irrespective of whether this person is present or not.
Whether they have died or not, they will pop into your head without your 'permission' as a reminder of a previous physical relationship, whether there were unresolved issues or not.
They served you exactly as they were supposed and will continue to serve you in your mind, from the aspects of them you loved and those you didn't love.
The process of mourning is to think about what the lost one meant to you and what your conscious mind learned from the physical interactions. Now that they are gone, the work solely lies with you to reconcile, though it was always with you, you just used to have the privilege of a novel form with unpredictable responses, which you have learnt enough about to digest yourself.
Their time in relation to you is over and while the ego may cling on to the lack of the physical embodiment that used to respond to it, they have served their purpose in this form and have become a part of you which may still require some integration.
The Illusion of Time
The more difficult situations are when it is someone that you grew a deep bond with over time, like immediate family members, spouses, close friends. People with whom the connection was so multifaceted and complex that there is a bewildering amount of information to integrate, and may take a lifetime to do. If you remain mindful of this, the synchronicities will manifest in your day to day and you must embrace them as part of the grieving process.
Some relationships are short lived and you seldom think of that person again. The purpose for you has been served more or less. They may manifest in your mind again through myriad triggers, be it the scent of a perfume, a Facebook post or just good ol’ reliable unconscious thought bubbling up to the conscious. It’s the relationships that end ‘early’ where you have to do the work yourself.
So think about them and what they meant to you, talk about them and remain open to the triggers. The triggers won’t stop but how you deal with them will change for the better.