Grief can cause a kind of identity crisis

Those with whom we have close relationships are not interchangeable commodities that can be replaced. So we grieve ultimately for how others’ deaths are losses to us.

We do not grieve the deaths of everyone but only those with whom we have a relationship that is central to our understanding of ourselves and of what is most important to our lives. These deaths can also evoke a kind of identity crisis ('I've lost a part of myself').