Person is immortal...
but what is immortal are the lessons they teach others and the way with which they live their lives...that is how one becomes immortal...
Think about living forever, think about watching your freinds and family die off. Think about seeing what you knew pass on, fade, continually replaced by new and different and strange things.
Think about human nature and how much people are really afraid of change, think about the pain of seeing people you love die, your fear of loving new people because you don't want to go through that terrible pain again.
The loneliness, and the boredom.
Think about being immortal, you can't die, but you can still feel pain, you can still be hurt. YOu may mend in time, but there are always reminder that pain is like an old freind that helps you remember you're alive.
Think about becomming immortal and not being in your youthful prime, think about not being able to relate to these young creatures who still are curious, you're bitter because you're curiosity faded long ago.
THink about how bland all emotions are, you are afraid to love, but afraid of nothing else, you can't hate because you know that you will outlast whatever it is you come to hate.
People don't know how being immortal sucks.
Anne Rice has come closest to describing the pathetic state of immortals, they are not creatures to be idolized, they are pathetic creatures that do not want or desire your sympathy.
If you wish to be immortal, you do not understand immortality.