Live Forever or Die Trying
Isaac Arthur's latest video was about the kinds of impact a much longer lifespan for the average human would havve on society. I also got the title for this post from the video. I am sure Isaac Arthur didn't coin the phrase because I've heard it before but it's a great saying.
Isaac Arthur didn't give it as an example but while listening to the video I was thinking about the Torchwood series "Miracle Day". In that story it wasn't immediately apparent that suddenly it was almost impossible for any human to die. Once people started noticing death was virtually impossible the news spread fast. In the story there was a group calling themselves the "45 Club" due to the belief that jumping off from a 45 story building or higher would result in permanent unconsciousness which was as close to suicide as anybody in that scenario could get to dying.
For technological extension of the human lifespan I don't think it would occur as suddenly as in that fictional story. There probably won't be a "Eureka" moment in which a nanobot is created that can repair cells. There might come a point at which, as the video describes, each year scientific progress results in the ability to increase the human lifespan by more than a year. At that point medicine would be outpacing nature.
With a few hundred years of life anybody could become an expert in multiple subjects. Modifications might need to be done to the brain in order to compensate for the need to then be able to keep track of hundreds of years of memories.