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You don't need to -- and shouldn't try to -- explain every detail of every bit of background you've come up with. If your writing says "I had to do lots of research to write this so I'm going to ...
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#3: Attribution notice added
Source: https://writers.stackexchange.com/a/25858 License name: CC BY-SA 3.0 License URL: https://creativecommons.org/licenses/by-sa/3.0/
#2: Initial revision
You don't need to -- and shouldn't try to -- explain every detail of every bit of background you've come up with. If your writing says "I had to do lots of research to write this so I'm going to make you read it", it's getting in the way of the story. _However_, you need to address anything that's reasonably going to interfere with suspension of disbelief. If your story's setting is going to have readers reasonably expecting cell phones and Internet services, you can't just ignore them and assume no one will notice. Here's the trick, though: _addressing_ it isn't the same thing as _providing a detailed explanation for it_. Will it suffice, in your story, to have some character refer to those times in a bit of dialogue? It could even be a time reference -- "back when the 'net worked, we'd spend our evenings reading Facebook instead of actual books". You don't have to explain all the details of how the haunters fried all the cell towers and reprogrammed all the routers or whatever, if it doesn't help your story. Just assure the reader that you haven't missed a glaring hole. If your plot element is particularly implausible, you're not doomed. There's a technique called [lampshading](http://tvtropes.org/pmwiki/pmwiki.php/Main/LampshadeHanging) (warning: TVTropes link) with which you acknowledge it in the story and then move on. It doesn't sound like that's your situation here, but I mention it in case you have other issues to address.