[pron]

Except there might be unseen consequences. It's all very hard to predict, but here's one example. Suppose human life is extended by 20 years. For some, it might be enough to start a second (or third) career. For others -- maybe not. Which means that people will need to remain in their career for a much longer duration, which might cause them considerable distress. Then again, maybe not.

[scobar]

There will almost certainly be unseen consequences. Some may be negative, but I believe the aggregate will be more positive (assuming senescence remains at least proportional to lifespan). As Newton stated, we may see further by standing on the shoulders of giants. As our species acquires more knowledge, the time it takes to learn what has previously been discovered often increases. Our average lifespan may become (or already be) a bottleneck to faster technological innovation.

Imagine those at age 100 preparing for the second half of their lives rather than expecting to die in the very near future. That may spawn a new phase of maturation that doesn't exist today. What if, generations from now, people recall how young and dumb they were before they turned 100?