A spin-off or carry-on of the term "mindfuck".
A temporary amnesiac state of mind endured by someone caused by the following scenario (or similar):
After one has been studying or researching intensively for a long period of time, he/she comes across a piece of complex information which warps him/her into a "mindfuck". The attempt of comprehending this mind-tangling data acts as the ignition point of an epic-scale memory implosion of the individual, thus, in simple terms, wiping out from short term memory anything the individual studied or learned in that long period of intensive study/research.
After a month of studying like an absolute fucking maniac for his exams, Edmund stumbles across Einstein's lost and unpublished answers to the Universe.
Edmund: Holy fucking shit... *blanked out*
Kyle: Dude, how do you solve this equation??
Edmund: I....don't....know....*still blanked out*
Kyle: Dude, you look messed up, did you get a mindfuck?
Edmund: No man....(long pause) I got a ROUNDHOUSE mindfuck