This one baffles me.
DS2 is convinced (god only knows why) that the sun stopped setting because he wasn't wearing enough blankets...that's why it was still light out when he went to bed tonight.
He also thinks that if he doesn't wear certain pyjamas or clothes or say certain things... that the sun will stop setting.
Not a clue where it came from or why this obsession with it. He was just relieved when the sun finally set, although was upset because it did not immediately get dark as soon as the sun disappeared. 
This is all he talked about for over an hour tonight... constant non-stop... demanding answers (which I didn't have) about what might stop the sun from setting and what would make it set... he wasn't remotely interested in facts about the whole reason the sun sets, etc.
Anyone else's DC come up with odd stuff like this? And what did you tell them? Because he was really intense (and upset) over it. I anticipate this being the new "stresser" here. 