The most important part of owning something is its sacrifice: it is given away, it is shared with another, it is abandoned to one fire or another, and it is let go of. This is the necessary consequence of owning something, even if it is not the purpose for which things are obtained.
All friendships end, even if they last the lifetime of one of the friends, the friends are separated. And there is reason to grieve and regret the loss. But what friendship is lost is not sacrificed. Not anymore than what is broken by accident is sacrificed. The grief and regret arises out of the holding onto, not the dearness, of what we have loved.
The elder holds tightly to their cane, or walker, but does not love the prop - on the contrary, the symbol of infirmity, the loss of youth, these are frequently reviled, and hated. But it is impossible for them to let go of. For they hold onto it through their youth. Sacrificing their youth, they may let go of their grief and journey to the next stages of their lives.
Any person at all holds tightly to their life, their body, they hold onto themselves - even to their work, not understanding the purpose for their working, for their life. What is earned must be enjoyed, or the work is not worthwhile. Kama is the purpose of Artha, the means of Dharma. Though death is the consequence of life, self sacrifice is the purpose for which life is lived. Whoever sacrifices their lives, day by day, hour by hour, by giving, sharing, even by abandonment, and lets go of it, lets go of grief and regret. And becomes worthy of accepting the sacrifices of the beings that provide their bodies and strength as food to sustain that life's work.
Some people hold tightly to the support of a friend and cannot let go easily. But this is not because they hold onto their friend - only the strength of that friend. Because they do not understand the purpose for their strength.