Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great book - tough topics!

This book got into the stuff no one likes to talk about, but that men need to know. At the start, the myths opened my eyes to truths about what happens as men grow older, and it clues us in to changes we can make to our daily lives.At first look, the book seems to be about assisting men with fertility problems, but it is in reality a book about sexuality. My "vitality" has improved significantly since taking the advice in this book. I'm thinner, more active, and, well, everything works better!One piece of advise, though. The second half of the introduction is really hard to get through. Skip it. Read through the other chapters.