I have an iPad 2 that got for Christmas 2011 and have looked after carefully.
The day I got it BIL set it up for me using a brand new email address that I've never used. i was a bit 
at this but he was trying to be helpful.
I then added my actual email address and set up a new Apple account linked to that and have used that ever since.
Yesterday I used the 'Find my phone' function for the first time in ages and had to add my Apple ID in order to do so.
This evening I was happily MNing and the iPad turned itself off, when i stared it up again it asked for authorization saying that a new account had been added yesterday and I needed to add the original email address that i can't remember and the password that I definitely cant remember.
The iPad is linked to my iPhone but that's only a year old so I can't find any emails etc. to show any information on it.
Anyone got any suggestions please?