While many of history's greatest social networks allowed the editing of content once it was posted from the get-go, the biggest of them all, Facebook, just activated the ability this afternoon. The folks at Facebook responsible for this update have suggested that you'll be able to edit your posts immediately if not soon, but at a cost. That cost - you'll need to know - is the addition of an "Edited" marker to whatever post you happen to edit.
This update is coming first to the web and to Android devices, believe it or not. If you update to the version of Facebook that was issued today, you'll find your ability to edit posts to be fully functional. This update hasn't - on the other hand - appeared for all users quite yet. It's a roll-out effort that'll be taking place over the next few days.
The last group that'll be getting the ability to edit posts shared from their device is iOS. If however you have an iOS device and a web browser that's able to give you desktop mode, you may find yourself working with the ability to edit posts on Facebook that way. That's a bit convoluted, but it may work if you're in dire need.
This update is appearing this week in the Google Play app store and online - though it's also true that not every single user across the world is able to edit just yet. The roll-out begins this week: that's what's clear so far. For those of you that remembered some sort of post editing ability in the past - you're not losing your mind. You've been able to edit some comments on posts as a regular user and, as TechCrunch points out, Page mods have been able to edit posts for many moons.