Immortality

"I don't want to achieve immortality through my work. I want to achieve it through not dying."

Yes, we don't live forever. People and animals change as they age, and eventually catch disease and die.

Eternal life is ingrained in the collective human consciousness, having been present in literature and myths for as long as they've been around. Literally. The Epic of Gilgamesh (the oldest heroic epic known to the modern world) is, in large part, about the titular character's search for a way to live forever.

Of course, having been around for so long, Our Immortality Is Different, and comes in several flavours. These tropes are not mutually exclusive; there's plenty of room for overlap.

Subtropes:

For general tropes relating to immortality, see This Index Will Live Forever.