I don't agree with the concept of dreams being subjective. Columbus was a drifter and a failure as a sailor. In his voyage across the Atlantic he was helped by an Arab sailor who had excellent navigational skills. He did reach new lands. Why and how he did what he did can never be known. Respected brother Shahalam has used the words..'must have trusted.........expedition'.We can't be sure how the mind of the opther person works. We all discover our Americas every day due to our efforts. All ideas and concepts can be called 'dreams';but the moment their covers are removed they become 'discoveries'. Dreams are usually defined as a unifying force of body, action, mind and spirit. They may lead to a better understanding of one's own self, but reality, general terms, may be different. It vrealtes to consciousness in matter (Brain)-----a very intriguing phenomenon. Adler considered dreams as an important tool of mastering control over our waking lives; more of a problem-solving device. As opposed to Freud, he believed that our behavioue is driven by power, control and motivation.
Day dreaming is not one sided. It is a combination of the subjective and the objective and generally leads to achievements if the person works hard to give a practical sdhape to his dreams.Dreams exist because of the person and outside his existence. He has to be conscious of his dreams as they provide him with a ladder to climb.
Remember the old couplet:
"Oth bandh kamar kya darta hai
Phir dekh Khuda kya karta hai'