There’s an old saying, from back before Contact.  You can be full of wisdom or full of youth.  You can’t have both.  That’s still true of the lower classes in places like China and India, where population and cultural pressures keep the treatments more rare.  But in most of the Western Alliance, and even in Russian and non-aligned territories, most people can learn wisdom through experience, and still be healthy enough to take advantage of it.  That’s changed everything.