I read this book in two sittings at Books-A-Million, which should provide some amount of insight into the substance therein: mainly that there isn't much. The book is by Steve Martin, so I wasn't expecting the autobiography of Ghandi or anything, but what I was expecting was a well-written delving into the mechanics of stand-up. I've seen Seinfeld's documentary, Comedian, and I was expecting something more along those lines, insight into the trials and tribulations of an upcoming performer.
In actuality, the book is divided into two unequal sections, the first and larger half detailing Martin's beginnings at Knott's Berry Farm and Disneyland, with only small portions talking about his actual standup. The shortest sections of the book covers his meteoric rise to superstardom in the early 80s and it's the only section that consistently lets us into Martin's head.
The last section tells us how Martin abandoned standup (Answer: abruptly and completely) and why (He felt he'd peaked and had nothing new to offer). However, the book doesn't explain why Martin thought that doing The Pink Panther was a more artistically viable option than singing “King Tut” a few more times.
The memoir is very well-written and contains some interesting and funny bits, but I found it a little underwhelming. If you're interested in the inner workings of comedy, watch Comedian. If you're interested in Martin, watch The Three Amigos and listen to Wild and Crazy Guy. If you're interested in the rise of a supercomedian during the 70s and 80s, you'll probably enjoy it, but except for a few poignant moments near the end, it's nothing more than light reading.