Perhaps some poor phrasing on my part. In another comment on this thread, Tim Ward argues that Nietzsche's idea was based on responding to life with a joyful 'yes', even in the face of all its suffering and pain.

We don't cause or deserve what happens to us. Not always, and certainly not in your case. If you've had those radiant moments that I know you must have while raising your son through those challenges, then it's a life worth living - even again...