Whatever did all these parents do before some but job came up with these ridiculous ideas no offence intended at all to you if you have been using this etc, I don’t have kids so I know nothing about the subject but honestly, people managed to deal with their babies just fine for centuries without these things and I’m sure some of them are now very helpful but the rest, Im sure most could do just fine without!Google ‘wonder weeks’ - it’s basically a theory that all babies go through periods of development or ‘leaps’ at the same weeks old age so you can predict how their moods might change and what new skills they will develop.
The skills predictions have been pretty accurate for my baby but it’s not at all to say it’s all happened in that one week that the theory claims, that’s how it’s become so popular I think though. With the moods there’s a placebo effect of putting any mood changes down to the leap that’s helpful, it becomes very unhelpful when parents look out for it and believe it’s a leap rather than something that needs investigating or stick to it so stringently they worry if the child hasn’t ‘leapt’.