One of the blights of humanity is frustration. Human beings are forever striving for pleasure and wonderful feelings of rapture and bliss which in analysing it, is only temporal in nature. Try as we might the problem is that in doing this, we are trying to convert the temporal experience it into something permeate, which cannot be done.
In hankering that which is lost, frustration ensues, grief may result. When it goes wrong, we try to fix it to make it permanent, but we can do it. No matter how hard we try, we cannot make that which is temporary permanent. And we know that we will be disappointed because the pleasure will fade away and we want those pleasurable feeling back again. Jesus said do not chase after those things which are here today and gone in a few minutes, but rather strive for those things that are permanent by its nature and therefore more satisfying. Trying to hold on to a relationship which is gone will leave you frustrated and grieved for as long as you hold onto it. All human relationships albeit long term, are temporal subject to this life. The only relationship it is nature is permanent is with God through Christ which is subject to life eternal.