After like an hour or so, your ability to edit any post except for the starting post of a topic goes away. You also cannot remove any post at all.
This is so that we always have valid content on the forums. For example, if someone comes on and starts creating drama, they cannot remove their comments in order to supress it. If they decide to edit it away in means to hide it, that wont work because we have the Edit History thing.
Basically, it's allows us to have any and all history here be available to us.
