Adam Conover’s TruTV educational comedy series, Adam Ruins Everything, returns tomorrow for its third season of myth-busting, with this season’s episodes ruining stuff like guns, sitcoms, and the video game industry. In the video above, Conover was kind enough to give us a sneak peek of next week’s episode, titled “Adam Ruins Sleep,” where he talks about about the mattress-in-a-box phenomenon, and why there’s basically no good way to buy a mattress.