Why/How individual’s who are ill or suffering can (seemingly) “choose” to live or die, but in generally good health we cannot “choose” to simply let go in the same way?

Question

It just seems in certain age or conditions there is a point in which a person can hang on or let go. Why is this not something we have within us at all times? How does the body register this. I understand how organs must be working and bodily systems, too, but how/why does the mind/body only accept this choice to pass on only when suffering?

Edit: I am not referring to physically harming one’s self to end their own life, but more the mental, psychological, & perhaps spiritual realization/decision that automatically influences the body to shut down on its own.

In: Biology

Answer 1

You got it in you at all times but your body is resisting with all he has.. because well its actually all he has.

There are people who were triwed to commit suicide by overdosing but didnt realize they only took placebos. They still got into critical condition even though all they took was a small amount of sugar.
Their Body was just ready to go down and so it happened.