I can only guess.

This is an example of PECS (Picture Exchange Communication System) for feelings.
PECS is one system (of many) that can provide a way for non-verbal folks to communicate.
Currently, this is not in use in our home, as Shortpants just isn't into it. Can only lead a horse to water... 

You stand in the middle of the room, screaming in a language only you understand. Tears are streaming down your face as you clench your hands into fists, shaking with emotion. Is it rage? Fear? Pain?

I can only guess.

You look at me with an expression that I can only interpret as "HELP ME. FIX THIS. WHY DON'T YOU UNDERSTAND WHAT I'M SO PLAINLY TELLING YOU?" as the tears continue to fall, your hands continue to be clenched, and you continue to shake and scream and stare.

And I scream on the inside because I don't know what to do. I can only guess. And that guess, being so very important, is rarely correct. One in an infinite amount of possibilities as to what it is that you need different in this very moment. I scream on the inside until my voice disappears, to the heavens, hoping God hears my plea - but I can only guess.

You come to me, wanting comfort, wanting held; and then you remember. You remember that your emotions are directed at me, and it is my fault - whatever it is - and you claw and scratch and fight and bite and slap your way out of my arms and recover the expression that says so much, but I can only guess.

I want nothing more than to know the right answer: to remove guess from this equation that far surpasses my ability to solve for x; to be able to know exactly what you need, in the exact moment you need it, and to be able to provide it to you immediately - that is my wish, my hope, my need.

But I can only guess.