There are in the world a few people who never age. One such girl lives in Billings, Montana. She's eight years old, weighs eleven pounds, and is completely infantile. Of course, she will never be normal, but studies indicate that individuals like her have damage to a section of chromosome that causes developmential inertia, crucial to the process of development and aging. If so, it may be possible to halt the inertia processes at, say, age 35.
"If we could identify the gene and then at young adulthood we could silence the expression of developmental inertia, find an off-switch, when you do that, there is perfect homeostasis and you are biologically immortal."
Of course, disease or accidents could still take you out, but loss of muscle tone, bone density, and similar consequences of aging would essentially be eliminated; you'd be fit and youthful for as long as you wanted to be. Ah, but what might the cognitive impacts be? Would you continue to be able to learn, or would the brain go into stasis as well? Sure, you might never develop dementia, but would your brain freeze at 35? And imagine if your inertia was switched off at 25 - why, you'd likely be a liberal for all eternity.
Hell might be a blessing, by comparison.