Well, if we take the argument that content and context are inextricably linked to its logical conclusion, where we end up is that for me to fully understand anything you say, I need to be you. Perhaps I can partially understand what you say, based on how similar our contexts may be.
If our contexts are sufficiently different, the bandwidth required to transmit a translation of the background may be significantly larger than that required to transmit a translation of the foreground in question. Where do we draw the line? To admit that wherever we draw it is not good enough is a cop out?
I think that you are actually right here. I do not think it really is possible to understand someone. Not exactly as they mean it, not once you are talking about something complex, anyway. May be it's the difference between understanding someone and reaching an understanding. Through my training I have reached an understanding of O-Sensei's words. That isn't definitive and it doesn't mean that your understanding is the same as mine. If we share our thoughts and experiences we could be able to reach an understanding between ourselves. That still leaves room for each of us to have our own version of the understanding.