what do elves mean by "ageless"?

-Constantly releasing spores, the resulting children have some of their parents memories. if you can collect a hundred of these children, murder them and stick em in a blender, the resulting green plant goo should biomerge into their parent, memories intact. Peasants dump their spores freely, royal families keep close track of their children as insurance. Very vain elfs murder their babies to make clones.

-Re-incarnation with full memories. your baby just got up, paid you womb-rent then walked out the door. As is the custom.

-Whatever killed an elf slowly turns into that elf, they psychologically aren’t them but for all purposes in elf society they now are them and take on all their responsibilities.

-Return to the astral dimensions as a cosmic plant ghost. not exactly enlightened or benevolent now though and still holds petty grudges and wishes.  Has tiny cosmic sway in the universe, affecting probabilities, creating breezes and knocking over vases. Perfect for revenge.

-Whenever a tree dies, it re-incarnates as an elf. When an elf dies a tree grows. The few seconds wait inbetween transition is absolute bliss and  addictive. Addicts hide entire orchards of fell trees and dead bodies that look like them, very shameful.

- All elfs have beautiful self-portraits, made of moss, that age for them dorian grey style. Rich elfs enjoy entire  green galleries of themselves, and a peaceful immortality. Peasants wither and die as they desperately try to make a shabby drawing of themselves. Artists are highly prized.

-memories and psyche go to the elfs next of kin directly on death. Sometimes the new host is just like before, just with new insight on their distant relatives weird life, or the deceased’s memories take over the host's body.

-Upon bathing in the elf-spring, elfs shed their skin and de-age. A pact makes the spring neutral territory and un-claimable, but some really mean elfs are trying to find a loophole and get monopoly on it.

-Mother’s breast milk grants eternal life, but only to her direct children, and must be drank monthly. Literally everyone is still breastfeeding, even your great great great grandmother is still alive and suckling. To be weaned is to be shamed, disowned and sentenced to a slow death.

-elfs are a terraforming tool, the seeds in an elf’s wooden bones  sprout into sentient forests.

-The bugs that feed on their bodies are changed. They bury themselves deep underground and cocoon for a 100 years like a cicada. Emerges as the same elf they ate.