Many thanks.
I knew I had graduated to Trust Level One. I got a notice. But I couldn’t find out much about exactly what that meant, just the bit in the automodbot message that told me I had graduated (as it were).
I looked around for more info, but apparently not hard enough. I certainly didn’t think to go to my Profile Summary, expand the Badges pull-down, and click on a link in the one that didn’t have a badge.
Not exactly a disused lavatory with a sign that says “Beware of the Leopard”, but it would have been a while before I stumbled across it without help. 
Perhaps something like that could be made more easily uncovered?
How far up the ladder does one need to get to be able to edit their post? It isn’t a big deal, but I’m a bit surprised it is a privilege guarded so assiduously.
Anyhow, thanks for your help. I’ll be sure to come to you if I have any more silly questions like that.