When you get right down to it the link just below really can't lead us to true understanding.
Source: Postmodernism - Wikipedia
For we haven't the ability to truly understand given just how limited we are. We're just not that smart, nor can we ever be that smart. And it's not just a matter of how big our brains can get, but in how efficient they can be.
There will always be matters we will never be able to comprehend, and that's simply the end of the matter. You get right down to it postmodernism is about how we can't know completely and perfectly considering what we can use to know. To make this simple postmodernism comes down to a matter of doubt, a matter of skepticism. And skepticism can never be a matter of faith or belief for we can never be absolutely right in any sense of the word.
It is never a matter of whether a subject must exist, but a matter of whether it exists or not. And when something does exist it has nothing to say about us as human beings. The fact that there are great apes native to North America just is, and what you feel about them doesn't make a damn bit of difference. Hell, as far as I know we may even have a species of hyena native to North America, with nothing that prevents such an animal from existing. Being able to levitate say 3 feet off the ground would make a huge difference in our lives, and change things dramatically.
For what is affects us and can't help affecting us. Given how rare they would appear to be bigfoots don't have much affect on us. But should they start to become comfortable associating with us much as bobcats, red foxes, and raccoons have, then our world would dramatically change.
But getting back to the thrust of this post keep in mind that we will never understand perfectly or even totally. There you have my thinking on the matter.