Dilemna or dilemma?

according to the internet its spelt dilemma with 2 ms and always has been.
But according to my brainpan its spelt dilemna with an n.
i know damn well my brainpan is right coz im not an idiot.
So what the hell is going on?
im assuming some kind of end of the world mass memory transplant scenario, obviously

Dilemna or dilemma?
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