A Very Punchable Face is an attempt to answer the question "Who is Colin Jost?" by small sketch like chapters that have very little to do with each other and also seem to have not very much to say about Colin himself. Some of the more interesting or personal issues are just ignored or assumed known by the reader. If you don't already know who he is and what he did in life, some of the passages in the book won't make any sense to you. Also, isn't it obnoxious to write a "memoir" when you're 38?
So who is Colin Jost? He is a guy whose greatest fear is to be mediocre. Understandable since he went to Harvard, married Scarlett Johansson and wrote and hosted for Saturday Night Live. Who in his shoes wouldn't, right?
I usually enjoy self biographical works because they are deeply personal, and while I enjoyed reading this book, it didn't feel that personal. It was filled with jokes, but they didn't do anything for the story. They were there just because Jost is used to think of jokes all the time. It held some personal anecdotes, but mostly event descriptions, with little interior revelation of personal thoughts and feelings and intentions. Of all of the chapters I loved the one about his mother most, even if it had nothing to say about Colin himself. And I swear he speaks more about the times he shat himself than, let's say, Scarlett!
Bottom line: The book doesn't say anything you probably thought you were going to read it for. The rest is amusing, but felt like a series of sketches and not something to convey how a person feels inside and experiences life. Also the writing was rather... well... mediocre.