You know when you have something on your mind, and everything around you just becomes peripheral to this one train of thought. Then somebody's around and babbling away, and the frivolity of their words are like a mosquito buzzing around your head. You just want to firmly tell them to shut up.
You want this silence to get lost in your thoughts, but you also want them to be silent to, in turn, notice your own silence and the clear looks of deep thought plastered on your weary face. Then maybe they will talk to you, and listen attentively, and probably give some advice. Maybe bullshit advice, the kind you definitely did not want to hear; or some condolences on your tangled web of brain mush. Probably nothing actually substantial, definitely nothing that will magically make everything make sense. But still, if they would just ask!