Why is it that you love the smell of some men’s sweat but not others? A man’s natural odor is a make-it-or-break-it factor for many women. In fact, its surprising sway was the inspiration behind this book. I once dated a guy whose smell I hated, even though he showered, and it was a major reason why I couldn’t take the relationship further. Later on, I met a man whose smell I love—and I married him (for that and his other amazing qualities). When I found out there’s a biological basis to my olfactory pickiness, I was intrigued.