The only point on which all post-modernists agree is a refutation of meta-narratives (and to be explicit: "here is no reality out there, it's all just human-created abstractions" is a meta-narrative).
A very, very charitable interpretation is that you are maybe conflating it with Frankfurt School of critical theory, because it is also somewhat used/based on psychoanalysis (sigh) (latest postmodernists use psychoanalysis way less, also post-modernism isn't built on it, contrary to critical theory). Postmodernism is mostly post-marxism though, while critical theory is mostly neo-marxist imho (also, i don't want to be too critical of Frankfurt's school, i think most of their bad rep is caused by bad vulgarization/pop-science, most critics i read don't seems to understand why it's wrong either).
I do think that the reason most people conflate the two is because of an idiotic canadian psychoanalyst who can't read (or at least, can't understand what he read), who _clearly_ has no degree in literature or philosophy, and try to appear smarter than he is. He invent citations of the books, and sometime state that Derrida mean something when Derrida hismself wrote the opposite. 8th grader would do better and their reading comprehension assignment. He is wrong. Read and think by yourself.
