"So I explained what had happened to the nurse on call, and he recommended that I go to the ER right away."

Sadly that is what they say anytime the words "infant" and "head" occur in the same incident.

Regarding the link -- it seems to me that children need to learn how to entertain themselves, just like they need to learn how to soothe themselves into sleep. The caregiver paying attention to other things and people helps teach the child that.