I think you are touching on a fundamental truth here but trying to dhelve deeper into the weeds and the "Why" behind it.
We as humans are kind of 'programmed' this way (being the curious and exploratory beings we are) and this in fact is a part of our evolution.
However - the simplest explanation I can offer is this basic fundamental/cosmic/basic/universal truth.
Good/Evil
Yin/Yang
Ones/Zeros
On/Off
Light/Dark
You get the picture.
While we strive to be forward moving ('normally' towards the former) and struggle to 'understand' the latter.
One cannot exist without the other. And while I may not "like or agree" with X, Y, or Z - I have to maintain a level of respect for it.
So take that into consideration when you are trying to wrap your brain around some shit that makes you say "I just don't fucking get it!" - You aren't supposed to...
Sometimes the lessons learned are just about as much of what you *Shouldn't* do, as well as what you should.
I had a dream about this in which *I* was God.
That was the lesson at the end, and it hit me like a ton of bricks - of affirmation.
You are right that this idea of duality, like good and evil, light and dark, on and off, is built into how many people try to understand reality. It is an ancient way of thinking, found in philosophies like yin and yang, as well as in systems thinking, computer logic, and many religious beliefs.
But here is where I have started to question things more deeply, and maybe you feel the same.
Yes, duality exists. Yes, opposites seem to shape our world. But just because good and evil exist, does that mean evil is necessary? Or that it should be justified? That part does not sit right with me.
Even Buddha spoke about suffering and confusion in life, but he did not stop there. He shared a path to overcome those things. He did not say that suffering is fine because it balances happiness. He encouraged people to choose awareness, compassion, and wise action.
That is where I think the key is. We can recognize the existence of darkness without accepting it as normal. We can see violence, cruelty, and ignorance without saying they are somehow part of a divine balance.
The world may be shaped by contrast, but human beings have the ability to choose.
So maybe the real point is not to simply accept that bad things happen, but to understand that we are not required to take part in them. We can understand the structure of the world and still choose a better way.
I think only a few people really start to question this whole setup. Most people repeat the yin and yang idea without asking if we are actually meant to stay stuck in that cycle, or if there is a way out.
I also liked your story about your dream. Sometimes these moments hit us with a strong sense of truth, something we already knew deep down but could never say before. Maybe that is when we begin to truly remember who we are.