[ghostpepper]

I think 1 could also be parents actively forgetting how hard it was. I think I even read a theory that the mother's brain releases chemicals during childbirth that help her remember it as "not so bad"

I also suspect that older generations were less isolated socially and it was much more common to have parents/grandparents/cousins/etc in the same house who could care for the baby for an hour while mom caught up on sleep. It takes a village to raise a child but we have no more villages, so people try to do it on their own and discover it's incredibly difficult.