True immortality cannot exist in this physical Universe. Entropy will eventually cause everything to be isolated and near absolute zero.

To be able to live for say several 100 thousand yrs, may be interesting I think increased lifespan (several hundred yrs) is within our reach within just the next few decades.

Regardless of how few or how many of the humans became immortal, how could they survive the eventual destruction of the Earth itself? Well, they might be able to leave the Earth, I suppose. But if it was only you? Or only me? I don't see that working out. And then there's the end of the universe to worry about, if you're truly immortal.

I've loved the subject of the consequences of immortality for quite a long time now. I think it would be at first, fun, then painful, then numbing. You would be the only constant and very quickly you would be alone, completely. 100,000 years, what about billions, you would become an unrecognizable husk of yourself, you wouldn't speak, barely think, what is there to think about when you've thought every thought. Why build when everything turns to ash crumbling in your palms, you would slowly end up simply existing, alone. Would you even remember who you were, what you were? You wouldn't even want to die, you would loose what it is to want, or would you already be dead?

So, to simplify, from my years of thought and research:
Mortals + Immortality = bad idea

I'd would allow everyone to know that secret. Even if it has certain negative repercussions, they'd fade in time. If I never get hurt, can literally NEVER die from ANYTHING, then what's the harm to me? Eventually anyone who had bad intentions with me would die. Eventually my Immortality would fade from interest, just like any other amazing thing that has ever happened in history.

I would take the opportunity to, obviously, become rich. Since I am Immortal, I can make investments and wait patiently for them to pay off. I could work regularly for a long time, and save up money and buy bitcoins, since they're a big thing now, and then sell them off when they prove to be losing interest, like everything else ever in history. I'm not quite sure how I'd become rich, but I'm Immortal, it wouldn't be too hard.

After I accumulate enough wealth, or make it so I have ways of making constant passive income without me doing much work, I'd go on and start writing. I wanna publish books anyway. If I'm Immortal, then I can write even more stories. I'd make this my only source of income and influence, until I run out of good ideas.

Luckily, since I'm Immortal, it would make sense for me to be able to learn various things, and live out numerous interests until their full course is done. I'd be a literal Jack of All Trades.

It'd be fine for me to change. The World is Immortal, I'm Immortal, Existence is Immortal, Change is Immortal. I can do whatever I want, be whoever I want. There would be enough space in my life to live out many different lives. So what, things change. So can I.

Love would be tricky. On one hand, everyone I love, and grow to love, will die. But at the same time, throughout my existence, I will have loved more people than anyone ever had, or ever will. I will experience love and hurt and pain, but I will live through it. Pain is a part of life, and massive pain is a part of Immortality. As long as I build relationships I don't regret, how could I rue their passing?

Immortality would be Amazing.

There is a TOTALLY GREAT movie that deals with this very topic.

"Man From Earth"

My wife and I watch this every year at Xmas time. It's our guilty pleasure that was written by famous Sci Fi writer Bill Bixby on his deathbed. Watch it with some of your "true believer" friends if you want to TOTALLY mess with their heads.
This is one of my top three movies.

I have no idea... as it is plenty of times I feel I have enough of this life in this world but I won't trade it for the unknown... I still like it here... I think I gonna stay as long I am allow to be. Tired or Not Tired of it. Existing without a concept of time and space is beyond my little comprehension. Everything that is born must die. So... if souls are not born can they be destroyed? Maybe there is really no souls... maybe there are only spirits that move from one human at death to another on birth. Maybe broken spirits produce broken humans. And there may be those with little souls. Immortality means absence of Death... I want to Die one die just as everyone else I know will one day die. I do not expect to see anybody i know in the "afterlife". Many religions grant immortality to the soul. I am not religious. I expect me not to live in any shape or form to the end of times.

watching your kids get old and die and all your friends and finally when the world ends floating around in space self-healing. this is a curse for sure.

I don't like the idea of it. When my time is done I just want rest. I want my ashes put in a pine box and buried in a quiet place. I would like a halloween design on the box, though!

Painfully boring, I would imagine. Also, you would outlive everyone you cared about, which would be sad. Just my luck, I would commit a crime and end up being sentenced to 'life in prison'...

it would be a terrible curse in the end.

It would eventually become nightmarish. As you stated "I face a future completely on my own"

I asked this question in another forum and was surprised to learn that very few people liked the idea of living forever. Ray Kurzweil claims that we will be able to cure death within the next 15 years. Other knowledgeable scientists say it will take longer, but few deny that it could happen... I think it's not too early to be giving serious consideration to the prospect. When that pill comes out I'll be the first in line for it!

But it won't be just for one person, or even just a few. They used to say that if portable telephones were ever invented only the wealthy would have them, and that was true for a brief moment, but look at things now.

Think of all you could learn and pass on.

There was a very good film called "Highlander " that portrayed a small class of people who were immortal. The answer seemed to be they had to be very resourceful as they had to live in a mortal world without being spotted,,,not an easy task
I can highly recommend the film,