Memento mori: (Latin: “remember (that you have) to die”)
The
medieval Latin theory and practice of reflection on mortality,
especially as a means of considering the vanity of earthly life and the
transient nature of all earthly goods and pursuits.

Mono no aware (物の哀れ): (Japanese: “the sensitivity to ephemera”)
The awareness of impermanence (無常 mujō),
or transience of things, and both a transient gentle sadness (or
wistfulness) at their passing as well as a longer, deeper gentle sadness
about this state being the reality of life.

L’appel du vide: (French: “call of the void”)
The
psychological phenomenon in which people, with no desire to die, find
themselves faced with a steep cliff and experience a strong desire to
leap.

Amor fati: (Latin: “the love of one’s fate”)
An attitude in
which one sees everything that happens in one’s life, including
suffering and loss, as good; or, at the very least, necessary.