No information is stored.
There is almost no way to proof that a certain account belonged to you, since we don't store anything about anonymous accounts. There is no detail stored about your device, ip, location, email, name or anything else that could tie you to an account. Therefore there is no solid way of establishing the accounts owner.
What if I told you personal information?
Even if you would provide us with details about what we could find in your account, we are not able to help you. General comments and titles of forests are easy to guess as well as the last login date.
What now?
The only, unfortunate, thing todo is to create a new (registered) account and start over.