I suspect this is it in a nutshell, Anna. I’ve noticed way too many warm, empathetic women turn into narcissistic fruitcakes totally focused on the new kid. Sometimes it wears off after a few months, sometimes after a few years, sometimes the mom follows the kid to college. They say the most insensitive things, then go into weepy mode when they suspect someone has said something “mean” about their kid (or them in connection with their kid). I guess it’s an evolutionary benefit? Because a lot of times I have to think the kid just ain’t worth it.