How you change with the second baby, an empirical study, part IV: Rolling over

With the first baby, you read a lot about her physical and emotional development. You know each day not only what new skills she's acquiring but also how to help her develop those skills further. You perform a series of gentle physical exercises with your baby each day and you're really looking forward to her reaching her next big milestone: rolling over. You have a feeling it will happen soon so you video every play session because it would be a disaster if you didn't catch this special moment on film. You're excited for a week, announcing to all your friends and family that your baby might roll over soon. Then you're worried for a week because you would have expected her to roll over already, is there anything wrong? When she finally does roll over, you send that video to everyone in the family, followed by numerous videos of her getting even better at rolling over! Then you start getting excited about her sitting up by herself. You have to start reading about that!
With the second baby, all of a sudden you realise that your baby's as old as your first born was when she rolled over. When you come back into the lounge from the kitchen one day, you get a bit excited because your baby might have rolled over. You're not sure though because you can't remember if you left him on his tummy or on his back when you left the room - so he either rolled over or he hasn't moved at all. Mental note to self: avoid leaving the baby unattended on the bed for longer periods of time because he will roll over eventually.