"Nostalgia ages people, but science fiction is a literature of youth. Its spirit is the youthful yearning for new worlds, and new ways of living. Mainstream literature is like Chinese baijiu, tasting better as it ages; science fiction, on the other hand, is like tap beer—you’ve got to drink it quick. Read today, even the sci-fi classics seem feeble, not revelatory. The nature of science fiction is to shine brightest in the present, then to be quickly forgotten. But science fiction shouldn’t be afraid of obsolescence. As a literature of innovation, it uses a constant stream of inventions and shocks to hold back obsolescence, like an everlasting fire. Just as ash falls, the flame springs back to life, emitting dazzling light. To accomplish this, it must hold on to its usefulness."