Why cant you just go with your old account? If you forgot your password, you can reset it using your email address, if you no longer have access to your email address, you can change it in your profile settings.
I am assuming OP never wanted to be tagged for waking up from long period of inactivity. Maybe a random user could tag him alleging that he is posting in different boards or has a deteriorated English over the years. If this happens, no one will come to the aid of OP.
I can say that he is smartly reporting that he is the owner of 98789 and also he has a new account. If he is actually the owner of the old account, there's nothing wrong in using both accounts if he wishes.