We are sorry to inform you that you are a little bit out of the loop/uninformed/clueless,
Permanent Editing (the ability to edit posts of any age) was added in HF17 aka "simplicity" 2 years ago. You can see the relevant post here:
https://steemit.com/simplicity/@steemitblog/update-on-simplicity-cutting-complexity-with-steem-0-17-0 If you dont believe us go to a 9 month old post of yours and try to edit it, you will see you are able to do so just fine.

You're right there. I just checked by myself it's possible to edit a 12 months old post.
As I'd never need to edit a 9 months old post, really didn't notice that.
My bad and apologies on that respect.

Keep doing the good work for the community.
Have a nice day.