Jeanette Winterson's latest novel, "The Stone Gods," is set in the future on a distant planet whose resources have been over- exploited by colonizing humans.
In Winterson's world people can genetically "fix" themselves at whatever age they please. What age would you choose to stay at forever?
In the novel, most women fix themselves at around age 20, and never get physically older. Most men fix a bit older, though some fix as late as in their 40s, and go for the mature/wise look. Some women, pandering to some men's Lolita complexes, want to genetically reverse themselves to appear physically as if they are 12-year-olds.