I rather like this irreverent “Shmoop” explanation found at http://www.shmoop.com/postcolonial-theory/
“Imagine this: people come over to your house, while you’re still living there, and decide to settle down. Permanently. They rearrange your furniture, force you to cook for them; they even tell you to say things like “‘wicked”‘ instead of “‘hella.”‘ You’d ask them politely to leave, but every time you raise the subject they shush you and remind you they’ve got guns. Big guns.
Then, finally, things start looking up and you push the intruders out, guns and all. Byee! But wait…they’ve been over for so long that your house no longer feels like your home. Worse yet—you might not even remember how things were before these folks came in. Or, you might evenlike how these people rearranged your home—and life!
Complicated, right? You’d think you’d feel footloose and fancy-free, and maybe you kind of do, but there’s all this anger, frustration, and confusion, too. Plus, where’d they put the cookie jar?
Okay, so take that tangle of complicated feelings and apply it all to an entire nation. And then multiply that nation by all the nations that have been “‘settled”‘ or colonized by other nations (usually England, but there are some other culprits too)—and voila! That’s postcolonialism for you. It’s all about the anguish of the colonized who have to deal with the aftermath of colonization.
As far as the theory goes, it’s also about a select group of academics who immigrated from some of those nations, settled into a new country (mostly the US and sometimes the UK, but there are a few other hot spots too), and started this whole business of dissecting English (etc.) literature for its colonizing impulses.
And the select of that selection are Edward Said and Gayatri Spivak. These two are kind of like the king and …
In general, they .. are dead set against the whole idea of a ruling nation; they’re all about resisting dominating countries and their art, literature, films, you name it, that go along with their imperialist ideologies.
Feeling politically oppressed? You’ve come to the right place.”