Memento Mori

Memento Mori, Latin for "remember your own mortality." This is another form of negative visualization that encourages a person to contemplate their own mortality. I know, it sounds morbid and creepy, but think about it - if we accept death and come to terms with our own mortality than we’re more likely to cherish our present life.

It is not death that a man should fear, but he should fear never beginning to live.
— Marcus Aurelius