Creativity does not mean starting from nothing and bringing something into being ex nihilo but rather building on what already exists. Isaac Newton, for example, described himself as a dwarf standing on the shoulders of giants. Thus, if creativity means adding to what exists or making new combinations of older materials (e.g. using words that already exist to form new sentences), then the key to creativity is breadth and depth of knowledge. In order for people to become more creative, they need to learn about their area of creative endeavour (good poets, for example, constantly read poetry and other forms of writing). Next, people need to practice their skills in an area. Musicians, dancers, scientists, etc. who make major innovative contributions to their fields work extremely hard, often spending months or even years struggling in a specific area before achieving a breakthrough.