Ah, OP, then can I ask, genuinely, if you know exactly what it is getting at?
I can't be arsed to search my posting history (under diff name) but my PFB behaviour involved me sending my elderly mother back to Boots because she had accidentally bought non organic apple juice for babies. You know, the one Heinz make for babies.
She actually went back to swap it. I actually let her.
I would NEVER have done that with subsequent DC's. It was all about the obsessiveness of perfect parenting.
Of course all DC's are precious. But in context of MN, I always take it to refer to a certain type of behaviour usually (thankfully) only seen first time round being a parent.