When I'm reading a philosophical work, and I have to put it down, I usually have to skim through the paragraph or two before I stopped to put myself back into the train of thought necessary to move on. I picked up my Cambridge Companion to Augustine to resume my reading of the chapter on his political thought, and I skimmed the paragraph I had just finished before I put it down. (Mind you that this was also in a darkening room at the end of the day without yet having the light turned on after several hours out in the sun.)
This is what my mind interpreted the author as saying: "Augustine intimates in one place that rubber bands count as societies." Something didn't sound right there. Augustine wouldn't even know what a rubber band is. So what was it that I had just misread? Oh, right. I'd even typed up notes on this earlier today. Somehow replacing 'rubber' with 'robber' didn't occur to me without having to go back and read it again to remember what it really said.
I wonder if this is partly because 'rubber band' functions as one word in my mind and not a compound of two things. It's not a band that's rubber. It functions as a unit. Also, the different kind of band plays some role here too. I was trying to figure out what other kind of band Augustine might be talking about, and nothing came to mind, because a robber band isn't another kind of the band in the sense that a rubber band is a band.