When you go too school and they ask you " what is 3x*9g/7^r.33333333333333333333" then goes over to your desk and says "HURRY UP LARRY THE ANSWER IS DO AT THE END OF CLASS"
Teacher: " what is 3x*9g/7^r.33333333333333333333"
You: Shut up, my one brain cell is working very hard right now!!!
Said of an individual, circumstance or location perceived as insidiously annoying. Usually one discerns the circumstance after a brief period of interaction with said annoyance.
From direct translation of the Hebrew saying popular in Israel.
Eating One's Brain example:
Last time we were there, the guy was eating my brain.