“Seriously? This isn’t 6th grade English. You don’t get extra points for proper grammar.”
What’s the matter with correcting myself? Points or no, it’s quite common to do so on internet message boards.
“What’s the matter with correcting myself?”
Unless it’s done to clarify what might be misinterpreted, it’s:
Annoying and a waste of bandwidth.
An insult to readers which suggests you think they are not bright enough to instantly know what you meant.
A means used by the insecure, obsessive, or pedantic worried about appearing to be ignorant.
“it’s quite common to do so on internet message boards.”
That’s the problem. Think of how confusing and cluttered these boards would be if everyone posted additional messages to correct obvious mispellings.