If there is a sense of reality, there must also be a sense of possibility. ~ Robert Musil
Being open to possibilities opens up entire worlds of potential for you. It's a delicate balance between what is and what could be. While you dream it's important to stay in touch with reality, to not gloss over things with an idealistic sense or lie to yourself about the realities of a situation. Having a healthy understanding of "how things are" allows you to change them, but first you must accept & acknowledge the hard truths in order to be effective with the work.