I'm already guilt ridden that I thought to use this movie as part of an argumentative foundation for this topic, but
Interview with a Vampire deals with this idea of eternal life, albeit mildly, when contrasted with the time line of normal mortals. One question I think that should be asked instead of '
Do you really want to live forever?' is 'Can you handle living forever if the rest of the world changes without you?'
Since we are discussing a theoretical situation, let's say that if you could live forever, you would either go it completely alone or you could take select people with you. The social element is the most boggling one when talking about eternal life. We could all handle watching technology or history in the making, to witness all the linear noteworthy evolution of generations. With such access, one might say, you cease being a human at all, since all the aspects of what we know as human would no longer apply to you.
You would be isolated from anyone with whom you had a considerable amount in common, you wouldn't be able to express love fully because they would always be dying on you, and you wouldn't get to participate in the lives of others at their pace. You would, in essence, become like a god, manipulating the circumstances because you can see past the present into the predictable future, one you have had vast experience with before.
I am not immune to the dis-satisfaction with the present of the forseeable future, but I am not so unhappy that I believe that getting more time is going to solve anything. We are often more likely to want more of what we already have available to us, in a new wrapper. Rather than work through the life we've found ourselves in, we want a new life, a fresh start, unaware that the same follies await us no matter how many chances we get. We are human, and we are only capable of so much emotional upheaval and social change.
To understand our limits is, I believe, a more mature place to start than to assume that we can handle more than we've ever been given before and assume a diety-like existance. I have a hard time accepting that we are as bitchin' as we think we are.