Early in childhood, in the same year, I lost two much-loved pets -- a turtle and a cat. It is quite unlikely that there was any connection between these deaths.
However, I was left with the impression of how tidy the process was. Both opted to quietly disappear to a place of their choosing, a place they would associate with contentment while alive. When found, they were neatly posed and peaceful. Those deaths did not leave any real negatives, besides the fact that I could no longer interact with them.
Later in life, I lost several close friends and relatives. Strangley, I judged their deaths by the same criteria as I judged my pets' deaths. There was a real comfort in seeing them pass tidilly. And this is exactly what I would want for myself, if I am able to have any say in the matter. I have not the least desire to stay alive, just for the sake of it, after quality-of-life sinks below a certain threshhold. Even more importantly -- I would not wish my loved-ones to witness an untidy passing.