When someone is sick, in a way that isn’t going to be solved quickly, people always rush to comfort and help this person. We bring them their favourite things, we take them to appointments, we do everything within our power to ease their suffering.
But there comes a time for most people that they have put in enough effort. That moment one realises that this person may never get better. Psychologically it can be very straining to deal with an illness, but also with an ill person.
Sadly a large percentage of people who are either terminally ill or have no prospects of their sickness ever going away, that experience the loss of friends more so than others. They are abandoned. Not by any intention or anguish, its just the way it works in some cases.