Since Friedrich Nietzsche evidently had to wait until death to know if his belief was accurate or not, he can't exactly weigh in on the proposition now. But there have been a lot of people talking about life after death experiences who can weigh in, Dannion Brinkley being one of them.
I suspect it is true that that which kill us, also makes us stronger.
Life on Earth School is one small piece of eternity, one wave in-between many waves of the Great Continuum.