I fear you miss the point.

It's not finding the thread that is the problem. It is having it turn up for any search regarding 'groups' or 'manipulation' or 'iteration' or 'arrays' or ...

It will now turn up on so many searches for unrelated subjects that you made searching less effective rather than more.

It is very doubtful if anyone else will come looking to solve the same problem I had -- it is pretty unique -- but if they should, the chances are they won't know how to describe it well either and even less likely that they come up with a sufficiently similar description to you to pick that thread out.