Since I left university 15 years ago

with a master degree in mathematics, my understanding of the laws of the universe has mostly dissolved. There were some laws that made great sense to me, like Maxwell's and Schrödinger's. These were laws that you could intuitively feel would pass the test of time. I felt a little awkward about Einstein's relativity theory but there was rather little arguing with it.
However ...
Much of the theory about formation, lifetime and death of stars has always seemed very speculative to me. The lethal blow to my faith in astronomy came with the following message, which I reformulate here in its Wikipedia shape:
Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe, while dark energy plus dark matter constitute 95.1% of the total content of the universe.
I have no alternative theory, but the fact that 95% of what should be there does not interact with our capability to measure, leaves a high likelihood that reality is a bit different than our current theories have to offer.
So, when someone comes up with an alternative theory for what's out there in space, I'm much more receptive than if another quack comes up with a perpetuum mobile on earth.