As a sleep coach, I talk to new moms all the time with their own mom in attendance. And Grandma will often remark "I don't know why babies don't sleep these days. In my day, we just put them in the crib and walked away and they slept". Well, yes. Right there folks- I just gave my baby space to learn and she did it on her own. Sleep used to be, like many things about parenting, different 20+ years ago.