Iphone unlock

I have an iphone4. As it was my first iphone I didn't pay much attention towards the apple id and password which i setup on that phone.... and when the phone storage became full i tried to factory reset it without deleting the apple id on it.. After factory reset when it switched on, it's asking for the apple id and password which was saved in it.. and the problem is I don't remember anything about that apple id... it's stuck on that activation screen since years...

Is there any solution for this?