It's been said, regarding history, that "Everything repeats over and over again. No one learns anything, 'cause no one lives long enough to see the pattern..."
...but what if someone did? -- Anon Guest
My name is Loth. It rhymes with moth. I've taken up variations on the surnames Smith and Jones, all over the world. I know a lot of people who do illegal things to make certain my identities are stable. See... when you're immortal, you don't always want the people in charge to know.
Try spending fifty years in Bethlehem, some time. Fifty years, unageing. Fifty years before someone who had been there long enough deigned to notice that I looked exactly the same without the kind of genes you need to be effectively ageless. Try only being released when said doctor actually witnessed you taking a fatal injury and then getting back up again.
And no, I don't know why I'm immortal. I just am. And believe me, I have perfected the art of staying the hell away from medical science. Nope. Not going near that. Fifty years in Bedlam was enough. Another century or so while modern science slices, dices, and juliennes me is not on my to-do list. But... that said, there are still times when I try to stop bad things from happening.