Who else forgets to close their OBS after they /host other streamers at the end of their Twitch stream? The fool who owns this website and this nifty activity graph certainly has.
Apparently, I streamed a whole 8 hours legitimately, which is honestly surprising considering I can barely sit through a 2 hour movie. During these hours, I saw the standard fluctuating activity, hovering around my typical numbers for an art / gaming variety stream. And at the end of the night, I've gotten into the habit of being a good twitchizen by sending over a /host command to one of my friendos, or in some cases, a random creative streamer.
Turns out, if you don't close OBS after doing this, your stream will activate again when your hosted streamer finishes. On this "magical" night, my viewers were treated to a black screen accompanied by the sounds of total silence interspersed by my occasional sleep talking.
Friendly reminder, TURN OFF YOUR OBS WHEN YOU'RE DONE.