"I can't imagine..."
This phrase is really annoying to me. So much so that it now ranks as one of my top pet peeves. I dream of one day responding with, "Imagine it...go ahead...TRY to imagine it...you can do it."
I find I don't have such a negative reaction when someone says, "I can only imagine." It says, "I know it's horrible and I can't possibly REALLY understand it...but I can TRY to imagine it and it is bad." I think it's because the person saying it has at least "gone there" emotionally as best they can.
Or maybe I'm just too picky.