In the beginning there was Nothing.
Nothing was a cool kinda guy, who enjoyed hanging out by himself and doing Nothing. Now before you go judging this poor dude, bear in mind that he was literally the only thing in existence, so doing himself was pretty much the only option for things to do.
Because there was only Nothing, and due to a funny little quirk of space-time which means Something is required for time to actually exist, Nothing just did himself for all of time. And for no time at all. And every amount of time inbetween. Honestly it's all a little confusing, and when Nothing tried thinking how long he'd been doing Nothing, and whether he was or wasn't sore because of it, he got bored thinking about it and divided by himself. Or 0, as we now know it.
Since Nothing was the only thing in existence at this point, the fact that he divided by himself, 0, could hardly be called his fault. Honestly if a guy decides he wants to divide by something for kicks, and the only thing he has is 0, can you really blame him? The fact that he did it at all was both incredibly impressive, and monstrously disastrous. In this catastrophic event, Something was created. And not *just* something, but a whole hell of a lot of Something.
Something, by the very act of existing, and by no fault of his own, then forced Nothing into non-existence. Nothing had had better days. Except that he hadn't really had better days, since before Something came into existence there were no days.
Nothing cared not about such things, though. All Nothing knew was that he no longer existed, and that he had an inexplicable desire for custard. Except, because he no longer existed, he didn't really know that he didn't exist.
Only the desire for custard remains.