"What was that thought" is, itself, a thought, so the thought being chased away is being chased away by more thinking, I'm going to guess. Perhaps you mean that in attending to the thought there is silence there, but I doubt that as it wouldn't likely have been seen as a problem. So, since there is still thinking, you haven't lost the thought, it just changed. The mind changes so fast, there is no metaphor for that.
There aren't discreet "thoughts" to catch so much as "the thinking process" (citta) to be sensitive to, allowing one to gladden it, THEN steady it, THEN release it.
Of course all of it with the caveat that I'm not experiencing what you are, only comparing your description to experiences I do know.