One of the most frustrating mistakes I have heard in sermons is that of equivocation over the use of a word. The two worst of these are "dream" and 'vision". Words mean things in context, and what they mean in the Bible is generally not what many modern preachers think they mean.
There are two uses of the word "Dream", and these must be kept separate. The first is what we see when we sleep (like my dreaming that the Royal Wedding was being held in Bethel!). This is what the word usually means in the Bible, although of course the dreams recorded in the Bible are mostly given by God as revelations. The second meaning, and the one usually meant by modern preachers, is the meaning used by Martin Luther King Jr. when he said, "I have a dream." It means an idea of the sort of future you want. The word 'vision' is closely related. In the Bible it means a visual revelation given by God - the Book of Revelation is an extended vision account. But in modern language it more often means foresight, looking to the future, and having a plan for that future.
Now, there is nothing wrong with using 'vision' this way, or 'dream', but the problem comes when preachers take the Biblical use of the words and assume that in fact the Biblical use is the other use, which I have called the "Modern use" for want of another way of putting it. The Biblical passages are simply not addressing that - and that's the problem!
There are two reasons for equivocating in the use of words in preaching, and by far the most common is the desire to say something whether the Bible addresses it or not! But ministers are called to show themselves approved, "Rightly handling the Word of God." This is decidedly not rightly handling, and may I suggest that the preacher who really thinks that Joseph's dream has any connection at all with his own 'dream' of changing the world needs to leave the pulpit and take a course in homiletics before he comes back.