I deleted one of my answers a little less than three years ago. Today I discovered that the answer had been undeleted by three high-reputation users in August of this year. To the best of my knowledge I received no notification of the undeletion. Is this unusual? It's not something I've run across before.
I don't terribly mind in that this particular answer was undeleted, and I'm not asking that it be redeleted. (Some of my reasons for deleting the answer are no longer applicable.) Nevertheless, I'm surprised. It's not that the system allowed this to happen that surprises me—it's more that experienced users would choose to reverse another user's decision to delete an answer. I'm also wondering why there is no notification in this situation. Perhaps it was my original deletion that was inappropriate?
I am aware that self-deletion of answered questions is frowned upon and that such deletions are often reversed. Also I read somewhere that users can't self-delete accepted answers. But the reasoning behind those policies doesn't seem to apply in this case.