mind numbing = extremely boring

​Mind Numbing
The making of one's mind to feel numb, usually incurred by something either horribly boring or stupid. In the same way that your hand may go numb should you lay on your arm too long, and cut off blood circulation, the mind goes numb if you cut off relevant information for an extended period of time
EX)

I was listening to Fox News' mind numbing propaganda and nearly lost my mind today.

Sitting watchinf mind-numbing, sprit-crushinf game shows