It's hubris to think that we're not wrong about something completely fudamental

 Back before the spread of the germ theory of disease, people used think that "miasma," or smell, caused disease. This was incorrect. Before the discovery of sanitation before operation, people ridiculed the idea that they should wash their hands before surgery. For thousands of years, people thought that the Earth was the center of the universe.

For the entirety of human history, people have been totally wrong about something fundamental, to the point where modern day humans look back at them as fools. 

So why do we believe that we, today, don't hold a similar misconception so large and obvious to future generations that we'll be ridiculed for it? Why aren't we humble enough to realize that there's a probability that we're missing something major?

Not in the field of scientific work, of course. We know everything major about our natural world. I would be surprised if our conception of biology or physics was upended by a major discovery in the far future. However, there two (arguably one) places where I believe that we know just as much as the Romans did about bacteria. Consciousness. Religion. Until we find a way to fold these two things into our models of the universe, we're like the cavemen who drilled holes in skulls to release demons. People talk about uniting the standard model of physics, but what about uniting our understanding of science with our understanding of religion? What about finding an actual solution to the problem of divinity? Can we explain Jesus's miracles with science? Until we know the concrete answer, we're as much in the dark as our ancestors were.

Believing that we're not subject to major misconceptions about reality is hubris. Three hundred years from now, it's almost a guarantee that we'll be looked upon as backwards and stupid for some of our deeply-held beliefs. There's no way around this. 

My message in this post is to tell you to be humble about what you think is certain. The more shallow the evidence pool, the more taboo the subject matter, the more likely it is that we're totally wrong about something. So stop sitting on your high horse and realize that you don't know everything and society doesn't know everything. We know what we know and we don't know what we don't know. Keep this in your head and you'll be a better person overall.