It is not the first time that I notice a situation, when an old, already answered question pops up. Previously I thought that such things happen, since somebody has recently seen it and, say, up- or down-voted it, or left a comment (which is invisible, at least, not immediately visible).
However, today I see my own question asked in April again on the list. This was a very special question. At the time it gained no votes and had no answers. Finally I answered it myself. My answer also gained no votes. The subject seems to be finalized. However, it is up today with the same situation: still no votes and no new answers, or comments.
So I wonder, why did it pop up? What is the mechanism?