Work Hard, Dream Big

We are kids, and our parents, teachers, and elders always advise us to "Work hard and dream big!" I am trying to follow that, but I do not know how I can work hard. How can I dream big? To me, it is unclear what "Work hard and dream big" means... So, I am searching and trying to find the meaning of "Work Hard." I work hard at home doing chores. Should I do more? I have dreams when I am sleeping. Should I sleep for longer so that my dreams will be big? Or what it means... Let's read...Work hard, and Dream Big!