Okay, simple concept twist here. Said person is not on a quest, but is as smart as, say, Archimedes. Our hero discovered the underlying mathmatics of bouyancy, leverage, simple reflective optics, etc. during his or her first hundred years, putting themselves way ahead of the pack back in 5000 B.C. and incidentally discovering the fact of his or her immortality long before anyone else (and perhaps taking advantage of it--say by setting up as "THE IMMORTAL[insert archaic name here]").
Our immortal friend continues to make discoveries, but keeps most of them secret, only letting a select few benefit from the everincreasing store of wisdom and knowledge he or she has accumulated over the centuries, and eventually millenia.
Now, in the (insert favorite century here) century, our hero has discovered something astonishing. For the first time in the long centuries of life, he or she finds true love/another immortal/milk of human kindness/religion (aside from being worshiped)/all of the above.
It would be a great story...or several, if you had him or her discover them at different times...in whatever contexts.
JP
But you have to take the premise and make it your own. All science fiction (all fiction, for that matter) begins with the question "What if [insert premise here]?" But each of us has our own unique answer to that question. "What if my wife was plotting to kill me?" It's a pulp thriller cliche, until you supply your own answer, the one that no one else gives.
And that is what I'm asking...What if you were immortal, and possessed of advanced technological capabilities?
Would you play the Djinn, giving wishes to mortals and then playing cruel tricks on them in return? Would you play god, demanding the worship of those in your power? Would you turn your back on humanity altogether, and explore the darkness between the stars? Would you live a thousand lives, loving and caring, giving and taking, playing out each life until the time came to step offstage, and thence to a new role?
Each of us has a different answer to that question. And the question is no more than a premise. It is our answers that can beome stories, each one unique and our own.