When we learn to avoid death by age, we will be able to live as long as we can avoid death by illness or violence. That’s a different game.
What would life be like if a 300-year-old had as much to look forward to as a 30-year-old? I love science fiction about this, especially Heinlein’s.
The hardest time would be when the technology was only available to a few. The worst thing would be the news that you only missed it by an inch.
I really need to read some Heinlein. I can’t really imagine living that long, largely because while medicine is currently good at keeping us technically alive, it’s not very good at keeping our identity. I suppose avoiding death by age would require sustaining our cells. If that decreases the likelihood of being alive, but so mentally broken that you don’t resemble the person you were in your youth.