Q:

Losing enlightenment

I would like to ask if someone has known an enlightened being who lost it. 
Is there any Buddhist texts about this?
I believe it can happen with some brain problem maybe.

A:

Householder Seckin, those interested,
Actually many, most, believing that they have found awakening, but actually didn't, of what ever stage, sooner or later will lose that, often very painful and sometimes having cut themselves off from any attaining. This being the reason, the Buddha did not tell much on the matter that once having reached the stream (first stage of awakening) one is no more able to fall, right away destinated for full awakening, althought it could require another hardships within further 7 existences. So it's most empathized to focus on gaining right view, as the entrance and stick firm, till the "End" with the safe Bet, even there are many out there suggesting different, and stay not by first things first.
A possible more extended answer, as well as given space for discussion on go deeper, can be given found here: [Q&A] Losing enlightenment (possible?)
(Note that this is not given for trade, exchange, stacks or entertaining binding to world, but as exit for higher and beyond)

