Ultimately it doesn't matter whether you go forwards or backwards: you need to live your life as well as you can.
The wish fulfillment of growing younger is not necessarily all it's cracked up to be. You have new problems that arise which you are not anticipating and you deal with the same problems you would deal with if you were ageing normally: what is the end of life about? What have I accomplished?
When I met Richard Leakey, I thought, 'This is the most charismatic man I've ever met.' He has no legs. He lost them when his plane was sabotaged. But he's an interesting, sort of narcissistic guy.