In several of the discussions about closed questions, and also in the blog, there's claims that questions can get re-opened.
It certainly doesn’t mean “You are an illiterate cretin. Go away” — although some people take it that way.
Closed means “Closed for repairs”.
How often does this happen?
Ideally, this could be measured by the proportion of questions that are edited after being closed getting re-opened, but I guess a statistic on how many questions that have been re-opened after being closed, versus how many questions have ever been closed (including deleted ones), would be useful.