Death
Aside from wills, goodbyes, organ donations and funerals, there is important personal experience to decide to pass on, or not, when someone knows they may soon die.  Palliative care focuses on basic decisions people make when they are very close to the end of their lives, and it ensures someone is always available to talk to them.  It is a replacement for heroic medical intervention that may keep them physically alive but with no quality of life.  Human psychology must prepare for death if it is anything other than a quick surprise: