Lost your Login Key
There is exactly one way back in: prove you still control the Bitcointalk account this Academy account was verified against. That is the same Personal Text check you did originally.
We have to correct something first
This page previously said that linking a Bitcointalk account gave you a way back in. It does not, yet. Recovery through your forum account is designed but not built, and the button that used to be here sent you to a page that requires signing in — which is the one thing you cannot do.
So, plainly: if you have lost your Login Key, we cannot get you back into this account today. We would rather tell you that now than have you spend a week believing otherwise.
What that means
The account cannot be recovered — by you, by us, by anyone. That was the trade for not giving us an email address, and we said so before showing you the key. We are not able to make an exception, because an exception is exactly the hole an attacker would use.
You can start a fresh account. Course progress will not carry over.