This actually makes me think of something that Victor told me once, a couple years ago, when I was talking about having trouble sitting (something I have been having trouble with again, recently). I don't quite remember the exact context, but I was describing having trouble focusing on the sitting, and constantly found myself drifting "off topic" in the middle of an exercise. Victor noted that this was to be expected, especially when one has so little experience in this work. He also noted that sometimes, if we're able to simply acknowledge that a thought came up and put it away for later, and the same subject keeps coming up, that it needs to be looked at.
This also reminds me of a passage in Bennett's "Creative Thinking", in which he talks about choosing a subject and setting one's self to intentionally not think of it for a period of time. Impossible, but if we keep at it, then something new might come in.