The Monk Bought Lunch

My ghost drives around with a bag of dead fish*

Scientists may have explained that feeling you get when you're alone but feel as though someone is right there with you. That's all well and good, but how do they explain that feeling you get when someone is right there with you but you feel like you're alone?
Oh, right. That means you're hanging out with a scientist.
Naw, I'm just kiddin'. You're cool, scientists.

*that's just a Handsome Family lyric, nothing autobiographical here.