Honestly, I don't know! I've chewed on this pretty much ever since I had it, but I couldn't put my finger on any particular occurrence.
The closest I can come to explaining it is that it was my subconscious' way of assimilating my fear of my family? I had a... complicated childhood amongst some very specifically toxic personalities and always had the instinctive drive to not be like them, because it was shitty behaviour. I also feared them, because, like... I was a baby. They could literally crush me if they wanted to, and I knew it - none ever got THAT violent or crazy, just to be clear, but they were very on edge pretty much all of the time.
Maybe it was just the fear of getting caught up in that, of becoming that, but expressed abstractly, shapelessly because I didn't have the conceptual or contextual tools with which to shape it yet. And this is also sustained by the fact that that... thing felt very familiar.
Or maybe I'm reaching and this is utter nonsense, I have no idea!