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.