Wisdom. No match for the troublemaker Curiosity. - David Brin

Naroin stopped, shook her head. “Take it from an experienced hand, child. It’s no good blamin’ yourself for what you couldn’t prevent. Not so long as you tried.”
Maia’s lips pressed together. That was exactly what she had been telling herself. From the look in Naroin’s eyes, it didn’t get much more believable as you got older.

We already live a very long time for mammals, getting three times as many heartbeats as a mouse or elephant. It never seems enough though, does it? Most fictional portrayals of life-extension simply tack more years on the end, in series. But that's a rather silly version. The future doesn't need a bunch of conservative old baby-boomers, hoarding money and getting in the grand-kids' way. What we really need is more life in parallel — some way to do all the things we want done. Picture splitting into three or four "selves" each morning, then reconverging into the same continuous person at the end of the day. What a wish fulfilment, to head off in several directions at once!

Nothing is beyond us, the new legends say. So choose well.