On challenging Nietzsche

Good afternoon!

Today I was talking to a friend who, in her opinion, faces nothing but strife in her life. She expresses avidly that her life is a series of unfortunate, unjust and meaningless suffering. I sit there nodding and "hmmm-ing" until she finally stops talking to ask me "So, what do you think?"
At this point, I've learnt that when people are in the "I'm suffering" mode, it is best not to judge or think about what they say. Rather, absorb them and try to reflect back something of meaning, through asking them introspective questions. They ask and answer themselves. I have found it to be an effective technique.
So I proceeded to asking her questions about what the possible interpretations of all this could be.
And while I was listening I realized that Nietzsche's quote of "What does not kill me, makes me stronger" is quite imprecise and incomplete.
Lets break it down.
What does not kill me (aka any situation that is severe and harsh yet not fatal eg a failure, a personal defeat, a terrible traumatic experience, sudden and unexplained loss, severe morbidity)

Makes me stronger (ie. gives me immunity and strength to face further challenges)

I think that it should be rephrased. "What does not kill me, COULD make me stronger. But it could also make me bitter. Depending on how I choose to interpret it"

Everything is meaningless unless we put a meaning to it ourselves.
A death of a limb, leading to an amputation could make you stronger, because you've faced such a horrific loss of a much needed bundle of tissue, so clearly if you could tolerate this, you could tolerate more.
But it could also make you a bitter person. A person who feels inherent injustice and decides that this is not fair and I hate this world, it is so unfair. Why my limb? This world sucks, man. I never even asked to be born..and the downward spiral of world-hating ensues.

Suffering could lead to strength, but just as much, it can lead to bitterness. It's all about the interpretation.
Which leads us to another Nietzsche saying; "There are no facts, only interpretations"
The same way as there is nothing that is truly good..or truly bad. Everything is inherently neutral. We are the ones who put labels to it.
This is somewhat of a liberating concept. Imagine this, you can re-label everything you've ever experienced. A previously terrible accident, could be perceived as a blessing from the heavens, if you just decide to think of it so.