Who else thinks that theoretical immortality is acheivable?
Where did you buy that assumption from? If they were likely to exist, and we had some chance of seeing them, why do you expect that we should be able to see them? It might be better phrased that if they were likely to exist (which only assumes that there is at least one extraterrestrial in the huge, wide, open sea of the universe) what makes you think it would be probable for us to see some other life form not from Earth when life in space is highly unlikely (but not impossible)?
Define "interesting". I'm not interested in seeing some extra-terrestrial organism. I'm more interested in doing more math problems.

If you don't expect to survive that long, then what's the point of longevity?
But if you're not getting older the same way old people age, and are continually staying young, what would provoke you to "retrace" your steps? You would simply be doing the same things you've always done because you're not aging, and if you used to do something well when you were younger, you're still doing the same thing probably just about as well because you're not aging (if we are talking about something like sports, or some other strenuous activity you can do better when you're young than when you're old), and that might be considered boring. If you did age, you would notice that you are changing, and not able to do the same thing as well as you could. Even if it is undesirable, at least it's not boring to know you're changing.
I learned to ski when I was young, and then decided to try snowboarding because it was new--I also tried this when I was young, and didn't like it. It's not impossible.
What's that?
_________________
231st Anniversary Dedication to Carl Friedrich Gauss:
http://angelustenebrae.livejournal.com/15848.html
Arbitraris id veneficium quod te ludificat. Arbitror id formam quod intellego.
Ignorationi est non medicina.
I'm not at all sure I would wish to, either. I find this reality quite interesting enough. I feel no need to distort my perceptions with a psychoactive drug. I actually like my neural pathways roughly as they are now. Smashing them about at random is not my idea of a way to escape boredom (whatever that is...).
Hey... but don't get me wrong. I am all in favour of de-illegalisation of everything. It really is up to each person to choose when they wish to not longer continue their individual conciousness.
_________________
"Striking up conversations with strangers is an autistic person's version of extreme sports." Kamran Nazeer
I think effective immortality of the body might be possible. But even if that does happen, I don't think it would be all it's cracked up to be.
I think of the self as a fluid thing that changes over time. I am a different person now than I was when I was a child. And if I live for another 50 years I won't be the same "me" as I am now. So in a way the "me" that is currently typing this post will have died, even if my body is still there.
Extrapolate that out to someone who lives for 10000 years. Do you really think a 10000-year-old is going to even remotely resemble the person they were when they were 20? I think you would change so much that the new "you" wouldn't be you any more. So how would that be any better than simply dying and making way for the next generation (who, lets face it, would probably be about as similar to you as the 10000-year-old "you" would be).
In short, change is a fundamental part of life. Change is also a kind of death. Therefore death is a part of life.