When the rumbling started I sprinted down the hallway and made it to the bathroom just in time for the Four Horsemen of the Apocalypse to stampede from my backside, laying waste to my home's septic system and my will to live.
You can't not assume things. I mean, I am assuming the continued existence of physical objects through linear time, right now. I am not sitting here saying, 'Wow, shit's still here! Again!' every few seconds.