There are plenty of reasons to write down your high goals and big thoughts, and one of the main reasons is you get to program your subconscious to seek out opportunities that will lead you towards the big goal or target. 

Donald Trump & Bon Jovi taught me both of the concepts listed in the title of this video. Trump taught me to think big and Bon Jovi taught me to write my life in pencil not pen, because you should always have the option to change your mind about your career or life path at any time.