You won't go crazy in one dream. But this dream can affect your worldview in such a way that you gradually, slowly exhaust yourself, drive yourself into frames, complexes and fears, and this can lead to loss of mind.
The human brain is a unique thing, its capabilities have not yet been fully disclosed. But some part of the population of our planet knows how people know how to whip up ideas to themselves, and some pros can inspire them to others. Gradually, these ideas become obsessive, in the future you will see confirmation of this in every little thing (because the person sees and hears what he wants, and only), and then it can turn into obsession. And there it is not far from madness.
According to the theory of potentiality and the poetry of potentiality, our whole life is a dream. A strange ghostly dream that we habitually call our life. It is impossible to get out of this dream. It's not scary, but strange. Strange ...