The passage of time for faeries is clearly not the same as it is for
mortal men. Some legends say that faeries are born old and grow
younger as they 'age', while many others hold that they are ageless
and forever young. While in faerie lands, mounds and burrows, time is
usually not consistent with the outside world. There are accounts of
men entering a faerie residence and sleeping but a night, while 50
years pass outside. If faeries age only a day for 50 years, then they
could quite easily appear immortal compared to humans.