'It is the world that has been pulled over your eyes to blind you from the truth' (Morpheus). That about covers it. Minus the insinuation of conspiracy. No-one is doing this to us, we do it to ourselves. You believe in a world, don't you? 'The world is all that is the case' (Tractatus). But if nothing is the case then there is no world. Just your story and mine. And if I don't like my story I can rewrite it. 'Believe whatever you want to believe.'
Yes, but it's not as easy as that. I close my eyes and open them again. The computer screen is still glowing in front of me. My table, my lamp, my cup of coffee. Suppose I wanted to believe that there wasn't cup of coffee there but a glass of ice cold beer. Difficult. But if I really work on it...
'Believe what you like, when you open your eyes the coffee will still be there.'
We are talking about a basic principle. I can write my own script, act in any way I want to act (within my physical powers) but the facts are what they are (including facts that resulted from my previous actions). Yes, but. This is all just some story. I've chosen to tell you the story of 'me at my computer table', which may be the most salient thing from my point of view at this moment, but in terms of the way the world is, it's a forgettable detail.
It takes all the resources of my imagination all my general knowledge to picture where I really am. In a country on the verge of turning into a Big Brother surveillance state, on some tiny disintegrating planet, a speck of dust in a swirl of cosmic disorder. 'This is not a pipe.' ('Ceci n'est pas une pipe.') I am not here. Or, rather, it's my choice. My physical location at this moment is the least relevant fact about me.
(You probably can't see where this is going, but I think I can.)