Well… A concept is subjective.
There isn’t really a suitable topic for a serious response, so I’ll just hide it in this tab here.
Honestly Postmodernism is a lot of things, it’s not just one structurally sound concept. A lot of things run by it though…
I’ll go ahead and kind of explain it (I’m probably not the most knowledgeable about it) but to make it more applicable and relevant to the forum, I’ll tie it into the idea of Databasing—something born from Postmoderism, and the reason why Visual Novels are what they are.
The Modern era had an idea that everything was one story. Everything that happens in history is part of a single solid chain of events that we can recount and explain. They call it the Grand Narrative.
The Postmodern perspective says “well there realistically can’t be a single Grand Narrative because it will never be objectively true” and states that each individual event in history is its own narrative. It gets a bit complicated when you get to the narrative of me explaining narratives, but the gist of it is that there is no one story; everything has different sides and perspectives, and there are always multiple narratives.
Naturally if you subscribe to such thought, you begin to have different ideas of meaning than a Modern era society would expect of you. If no truth is objective, and everything is to question, then how much does anything matter? (The answer is subjective lol.) I think this change in thought was the result of globalization, but that’s a different topic.
The postmodern thought brought rise to a strange interaction… Works can be created and compared without necessarily becoming part of a bigger story. This means if you, for example, create a VN with a protagonist that has amnesia, another creator can see your work, grab an idea from it, and copy it or parody it or reference it or twist it in some way… Oh, and without having to link directly to the source.
This means that any such idea (we would likely know of them as tropes or cliches) goes into a database. (Note: Not strictly a physical database. It’s a concept!)
Sooo where does this database fit in? Despite what Postmodernism says, it doesn’t make sense to not have a Grand Narrative. The Grand Narrative served the incorrect purpose (a strict “objective” take on everything that happens) but there is obviously still a greater layer where everything connects… That is where the database sits. The database isn’t a line of events, but more of a soup of ideas and events. I believe Azuma Hiroki hilariously coined this as the "grand non-narrative."
Things no longer have to serve purpose to a greater whole, but still may influence something else.
Theoretically a Grand Narrative could exist, but it is and always will be out of grasp.
All this is the difference between a “well that show didn’t achieve anything” mindset, and a “wow, that was cute and fun” mindset. That knowledge, the recognition that Postmoderism isn’t a refusal of meaning but a refusal of an objective reality, is what distinguishes it from something like Nihilism. A lot of people get that wrong.
Speaking of Nihilism, none of this matters and Postmoderism is dumb. We get some cute anime girls and a bunch of trashy Light Novels out of it though, so I’m not complaining.