Why should I register my account?
I was over in http://codereview.stackexchange.com and I noticed that I can post a question without registering or creating an account.
I have posted a question in http://codereview.stackexchange.com and noticed few cookies had been created. Also, I can edit the posted question.
I however, erased the cookies and revisited the question and I was not able to edit the question. I also cannot log in, although there is already a user created with the name I have entered.
So, just to confirm my suspicion
Now, the first and bottom ones expires after 6+ months.
Is this how SO determines?