This book made no sense to me (no, I didn't read it en español, that was just the best cover). I thought the characters were totally crazy, and couldn't relate at all to their bizarre obsessions and behavior. I could not for the life of me figure out why anyone in her right mind would look forward to bleeding out of her private parts, let alone what was so desirable about wearing a bra, or growing breasts in the first place, let along pubic hair (ew!). Later on, sadly, I would become all too familiar with these types of concerns, but Margaret and her friends' ways of dealing with these issues never did make sense, even then.
This book did do two good things for me: one, it helped me appreciate the short period of childhood still left to me when I read it and two, by preparing me psychologically to confront one day a complex system of pads and belts, AYTGIMM made me appreciate advances in menstruation technology I would otherwise have taken for granted.
This book really did it for a lot of girls, but in my opinion Judy Blume's done much better elsewhere (e.g., my review of Peeping Tony the Dyspeptic Pervert Boy Moves to Long Island).