Currently rereading Philosopher's Stone and it dawned on me that wizards don't know much about human babies

The two examples from the first chapter that went right over my head as a child but reading now as an adult are driving me nuts are:

First, Voldemort couldn't kill Harry. Why? Because he thinks he needs magic to do it. Harry is a baby. He didn't need magic. But okay, we can chalk that off to Voldemort being unaware of how fragile babies are, or being a drama queen who goes for the extra flair.

But what about Dumbledore, who appears equally unaware? He took baby Harry, this little bundle of joy who's just been through a serious traumatic event (which surely would raise his stress levels and in turn impact his already fragile developing immune system) and just left him outside his aunt's house all night. He didn't even bother to ring the bell or knock on the door. His aunt and uncle didn't find Harry until the next morning. Babies don't do well with cold. Harry could have easily caught a pneumonia or another illness and died as an infant.

TLDR: It's a miracle Harry survived as a baby but not because Voldemort was powerful - but rather because nobody around him knew how to handle a baby