So what do they dream about? Well, that might not actually be the best question. As adults we think of dreams as being about something, they have a plotline however crazy or mundane that might be. We also experience the world in that way, as a story. We talk about the things that have happened, cause and effect, a sequence of events. If we have an emotion we like to be able to say we feel that way because of something that has happened and we get really annoyed when that isn't the case. Unusual emotions as a result of hormones or illness really throw us, why are you crying when you have nothing to be sad about?? We dream the way we experience life, as a story produced from a jumble of things we've seen or done.
So how does a newborn baby experience the world? Again, we don't really know for sure since we can't ask them but it seems likely that it's not as a sequence of events. Probably more like a cloud of disembodied sensations and emotions. Strong arms, the sound of a familiar voice, contentment, hunger, sucking, the flavour of milk, the shock of a cold baby wipe, movement, a heartbeat, a familiar smell, contentment again. A newborn is swimming in a soup of sights, sounds and feelings that don't have a plot. They don't have to, they simply are what they are.
My guess (and it is only my guess) is that a baby's dream would be similar. Perhaps they recall a snatch of that lullaby you sang, or the feel of Daddy's arms holding them. They might see a face coming into focus or remember the taste of warm milk. A baby might feel warm, content, secure and safe in dreams just as they do in life.
We will probably never know for sure, but that's what I choose to believe! What do you think?