Take art, whether it's visual, music, dance, writing, whatever. Art is one of the things that's supposed to break down the boundaries between us and give us some common ground so that the lines of communication can stay open. But the best art, the art that really works, is also supposed to be open to individual interpretations. No one wants specifics in art except for academics. No one wants their work put into a box that says it means this, and only this. So we go floundering through galleries and books and theatre presentations, taking what we can, always looking over somebody else's shoulder to compare it to what they got, readjusting our own interpretations, until somewhere in the process we end up having processed entirely different experiences from the same source material. Which is okay, except that when we talk about it, we still think we're referring to the same thing.
No one really knows what you're thinking, it's that simple. They can guess at the reasons behind what you're doing,but they can't know. And how can we expect them to when we ourselves don't even know the reasons behind the things we do.