Over half of Earth's population are female - and yet they are still marginalised, not only socially/politically but scientifically. Medication is researched and tested primarily on men, knowing that the female body works differently, the construction of refugee camps or aid in less developed countries don't take the needs (and customs) of women into account etc.
Granted, it gets a bit redundant, reading chapter after chapter of (sorry to say it that clearly) male idiocy/superiority complexes, and you keep shaking your head - but there are real-life consequences to that behaviour, consequences that put female lives at risk daily. Perez brings everything together in the closing chapters... and it's eye-opening.
Men, wake up, look (and think) beyond your own experiences. It's not that hard! Women have to do it every day.