hard reading

Having the car at my disposal for a doctor's appointment today, I took advantage of some opportunities and picked up things I'd been wanting.  One of those came from a recommendation somewhere here online:  the book Queen Bees & Wannabes by Rosalind Wiseman.  I saw an interesting comment in passing that this book is useful to women without daughters of the relevant age group because it can help us explain to ourselves some of our adult problems with other women.

Okay, good luck parsing that one; what I initially read was phrased better, but I've lost track of where I saw it.
( Haven't read far into it yet, but there's this one passage already.... )

I don't get it.  Hopefully the rest of the book will help me figure out why that one passage hit me so hard.