I was working on a basement apartment in a house I'd just bought. I turned off the power to the entire house at the circuit breaker because I was going to be working around a 220 volt electrical outlet. Why? I have no clue, it was too long ago. What I do remember is that I stuck my rubber gripped pliers on the wires and got knocked back across the room from the electrical jolt. I hurt my hand landing on some tool, but was otherwise unharmed physically. An inspection of the pliers showed that the live wires had melted a nice pattern on the metal pincers. For some unknown reason the house had been wired with this solitary 220 plug separate from all of the power at the circuit box, thus leaving the wires live unless turned off at another circuit box hidden on the side of the house.
Long story for a stretch of a metaphor, I suppose, but I'm coming quickly to the conclusion that writing is a lot like that 220 plug. You throw words out there and you don't know if the power is connected or not and whether the words will shock and repel the reader, melt themselves onto the reader's psyche or if there really just won't be any juice in them at all.
Nothing like hanging out at a writer's conference to question whether words can conceivably have any impact at all. Mostly we are all hanging around, hoping for the happy accident of writing something that can melt metal.