This book was written by a mother of young men who is clever, kind, funny, and honest. It is EXACTLY the kind of book that should be handed out to boys (its intended target audience) upon entering 9th grade. But if your "kid" is already in college? It's not too late to pass this along to them, too.
Honestly, I also think the content is so good, that it's something that belongs in the hands of all genders, and even older adults. I'm a 44yo woman with a 7th grade daughter and 9th grade son. I felt I got something out of it for myself, both personally and as a parent. In the not-too-distant-future, both of my kids will read it, too.
(Let me address the first thing many parents will bristle at: the title. That WORD. I don't mean to shock you, but your kids know that word. If they're over 13, there's a one million percent chance they hear it regularly from the mouths of their peers/friends, videos they watch, in books they read, from their siblings behind your back. If they don't use it now, they most likely will at some point. Giving your kid a book with that word in the title says nothing negative about you or your kid. In fact, it gets directly to the point. You don't want a kid who acts like an ahole or who grows up to be one. Most people don't want to be one, either. So just get over that word and hand over the book. We need it in as many hands as possible.)
In the perfect tone and voice for young adults who are handed this book, Cartwright covers the bigger stuff and finer details that not all people who raise kids into young adulthood think to address (intentionally or not) in regards to family, friends, school, work, dating, physical relationships, online life, real life, their environment, people who are/appear to be different than them, themselves, and more. Then the reader receives plentiful touch points to know whether they are on the right track for themselves and the people around them. By doing so, she helps the reader be an active participant in preventing and stopping toxic masculinity (and all the harm it causes), which is good for the reader and our society, as a whole.
With just the right balance of humor, frankness, and self-awareness that she's using her Mom Voice at times, the author helps the reader recognize aholey behavior in themselves and others, then how to address it in all sorts of realistic situations. The content is genuinely practical and direct, an easy read our older kids will roll their eyes and say, "[SIIIIIIIIGH] FINE, Mom. I'll read it. Whatever." when we hand it over, but then they'll actually take the messaging and guidance to heart, because no one wants to be an ahole.