Because if you don't, you'll be miserable. This is not a book for beginners. I just don't like the "you'll learn charts or else" mentality here that is creeping into other knitting publications, and I am not alone in this. The patterns are great. Check it out of the library before spending your money on it. This is definitely a "buy later" book. Also, be warned, this book is overpriced, as are the others she's written. It is too bad a publisher like Dover didn't get hold of them--the price would be within reach of more people, and more books would be sold.