Book excerpt: Far from the grown-up she thought she would be, Tweet Sering, 30 plus and tormented by a raging discontent with stale notions of how one must live, strips herself of the trappings of adulthood-her job, her savings, her insurance, and even her credit card-and resolves to begin growing up again.In this memoir that is by turns sharply funny, intelligent, outspoken, but also pained and bewildered, Tweet shows her readers how being astray can turn into being astig (tough). Her essays remind us of long, late night chats with our favorite friend, so that the substance of the go for broke account of her journey is not muddled by easy sentiment, but shines with a desire to cheer us on into our own journeys of being a tough girl. An Astigirl.