It's good to know, but can you elaborate more on this in the context of the grandparent comment? Perhaps with an analogy to computers.

Brains are no computers.

Fully healing an aging organism suffering from at least one severe disease, while more reasonably closer to current medical technology, wouldn't leave the patient in as good a state as simply moving to a 20-year-old body.

Of course you wouldn't only heal one severage disease. You would also lengthen telomeres and do all sorts of other things that reduce aging effects.