I think the dreams built along with a relationships fall apart only because the dreams were meant to be shared with that person. So in wishing for the dream, it's not to say the dream is separate from sharing it with the person who no longer is present in the dreamer's life. Ultimately the dream suggests the complete unity and togetherness not only for cultivating the dream itself but also the unbounded love between individuals. Otherwise anyone can make their dreams come true on their own.