Pretty much when one feels like they're being microwaved. Usually due to an excess of bad Chinese food, stress, or whatever else drives one to a lack of sanity.
Friend 1: whoa, is Tobey okay?
Friend 2: yeah, probs just a case of microwave head.

Tobey: *stares into space like a zombie*
by Bweeeeent October 2, 2015
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