Living a very, very long time has a major disadvantage. Our brains have a finite information capacity.
Recent research has proven that our brains in fact grow new nuerons, living a long time would allow even more expansion of our minds. Furthermore, we would focus on remembering and integrating concepts, not facts, since facts would be easily and rapidly accessible through information storage devices, making us (if we chose to focus our learning in that manner) ever wiser. Pulling up a wiki entry on a fact in doubt would be nearly as quick as pulling out of our own long term memory. Existing drugs such as Donepyzil have been clinical proven to increase the length of time which memories remain intact, future advanacements will no doubt further this trend. Additionally, you are operating under the projection that in 50 or 100 years we will be identical to what we are now, which is not the case, it is likely that we’ll have implants which increase our memory capacity.
If we live long enough we would have to forget stuff in order to learn new stuff. Losing information is akin to death.
I forgot your previous paragraph, does that mean part of me is dead?
When you are dead you lose all of your past and have no future.
Which is alot different than having no past yet having a future, additionally, we are not the conglomeration of little tid bits of memories, our memories are integrated into our behavior, our behavior integrated into our personality, you do not cease to be who you are because you forget a few facts.
Then there is the matter of boredom. As the author of Ecclesiastes once wrote, There is nothing New Under the Sun. In the short run he was wrong, in the very long run he was right.
If you are so worried about forgetting things, then you can just do them again, which will be a new experience. Additionally, doing something now is a lot different for me than doing it 100 years hence, since I will have learned and grown tremendously in that time. There is plenty of universe to explore, current inflationary theory based understandings suggest that the ratio of the observable universe to the whole of the universe is the same as the ratio of a single proton to the whole of the observable universe. A universe trillions of trillions of times larger than we thought. Bored? - A bored mind is an empty mind.
Seventy years might be too short a time to live but ten thousand years sounds way too long. I would settle for two hundred healthy years, long enough to see seven generations.
Ten thousand years is way too short, give me a million healthy years.