Developmental milestones are helpful. They help doctors and parents watch for any signs that a child may be lagging developmentally. It is useful to identify developmental problems as early as possible, because often intervention can help a child catch up or at least prevent further delays.
On the other hand, developmental milestones have also been known to make parents neurotic and paranoid. Take for example, my daughter when she was seven months old. She was alert, active and happy. She sat early, responded to visual and aural stimuli and seemed on track for nearly all her milestones. Except one. She did not roll over. Ever.
When I would put her on her back, she was content. She did not seem to want to roll over. When placed on her stomach, she would scootch a little, play a little and then screech to be put on her back. She would not roll over herself. When I placed her on her back to sleep in her crib, I knew she would still be on her back in the morning. On the floor, with toys to her side, she would inch her body over, creeping toward them without ever rolling.
At first it was sort of humorous. But then we started to worry. Why wasn't she rolling over? Was she somehow disabled? Laughable considering the muscle strength she displayed when standing on my lap or pulling the toys in her gymini. Yet, still we worried. Why wasn't she rolling over?
We tried coaxing her. We lay on the floor with her, holding toys to one side. My husband demonstrated the rolling action himself, then rolled her over and over. Needless to say, our interventions were to no avail.
One day, when was playing on a blanket on the floor and she saw something she wanted -- the cat, if I remember correctly -- she rolled over. Of course, then she waited a month to do it again, just to torment us. Apparently, she had not read the milestone book.