It is rough if both parents are working. Lining up all the schedules and breastfeeding and whatnot is harder than it sounds, especially in northern (and southern) areas with less daylight hours. Just cooking and feeding and cleaning up after a picky toddler and baby learning how to eat can kill an evening. And then at least one is bound to be sick every other week if they are in day care…the list goes on for why plans have a low tendency to work out. See also mattlondon’s comment.