I have some answers that I voted on when I had a different understanding of the rules from what I have now,or feel that I was too harsh in downvoting. Rereading them, I believe my original vote was incorrect. Here is an example, where I downvoted, but I now think the answer is correct, and would like to change my vote.
However, since the author has not edited the answer since I voted, and since quite some time has passed since I voted, the answer is now "locked in". I cannot change it.
One way I found works is to fix minor glitches in the orginal answer, for example fixing some spelling mistakes, so it counts as edited and you can change your vote. But in general, guidance is to not do such minor edits, so I would like to avoid it going forward. Is there a better way?
Is this rule that you cannot change a vote once cast (and some time has passed - I think you have a few seconds right after you cast it to undo/change it) a global SE rule, or one that we enforce only on this stack?
What are the benefits of that rule? It would seem to me that to change your judgment as you learn and correct earlier mis-votes would be a good thing. Is there some history with being able to change votes later leading to pathological voting behaviours?