I was thinking about how we sometimes speak without editing ourselves, and we can have the experience of hearing ourselves as if we didn't know what we were going to say. This kind of immediacy of speaking can be discomfiting. Perhaps it is because some of us (and I count myself here) are so used to thinking about what we are saying while we are saying it that we confuse the thinking about what we are saying with the actual act of saying something. And it occurred to me that we could make this mistake about other mental processes, too.
Can we imagine a situation where a person says one thing but thinks they are saying something else? I think it is possible.
And I suppose we can imagine a case where a person interprets a text one way, but thinks they are interpreting it differently, too.