So I posted a question and then answered it(On normal Arqade) But when I hit the check mark it says "You can not accept your answer for 2 days" Why is this? I also searched the normal Arqade and the Meta for an answer.
You can also accept your own answer, but you must wait 48 hours to do so. After all, someone else may come along with an even better solution to your problem!
So the reason you need to wait before self-accepting is to encourage others to post their own answers to your question.