Why can't we remember being babies? I once watched a YouTube video explaining that it was because it was an evolutionary disadvantage to remember it better because you might do something like electrocute yourself with an electrical socket and then get scared before you know what it is. I'm guessing the research thought it was because people might become too scared to try things if they remember the incident too well. I believe that video was a TED-Ed video that no longer appears in the first page of YouTube search results. That video doesn't give me the information I'k looking for. Also, YouTube isn't 100% reliable. Also, from reading this answer, I think it's sometimes fine to ask a question when I Google information and can't get the information I'm looking for from a reliable seeming source. I know it's actually a YouTube video that didn't give me the reliable information I needed. I also Google searched "why can't we remember being a baby" and found the article Why can’t we remember our early childhood? as the first search result and it didn't answer my question so probably none of the search results do. I'm not asking the evolutionary reason we can't remember being babies. I'm asking the reason based on how the brain works.

My question is


  What is it about the way the brain works that causes people not to remember being a baby?


I'm guessing the brain starts in a simpler state. Then the brain takes time to develop abilities such as memory reconstruction. I think just like absolute pitch is an ability that the brain can develop with time, memory reconstruction is also an ability that babies' brains have not yet had time to develop very well. I also realize that even after that ability develops, it's probably not 100% reliable for everyone. Once, I went to the roundhouse in Toronto on a day that there was something going on. On that day, I payed for lemonade using tickets and then they thought I hadn't payed then somebody else said I payed and they believed him. I'm guessing the person whom I payed had developed a method of memory reconstruction that was normally reliable but wasn't reliable in that situation. I'm guessing she was so busy doing so many things with so many customers coming that the memory of my payment faded faster than it normally does and then she used the method of memory reconstruction that assumed that the memory of me paying wouldn't fade so fast because her memories of doing things normally fade slower because she's not so busy doing so many things so fast.
From the BBC article, there's a prediction about that:

Perhaps, when we’re very young, the hippocampus simply isn’t developed enough to build a rich memory of an event. Baby rats, monkeys and humans all continue to add new neurons to the hippocampus for the first few years of life and we all are all unable to form lasting memories as infants – and it seems that the moment we stop creating new neurons, we‘re suddenly able to form long-term memories. “For young babies and infants the hippocampus is very undeveloped,” says Fagen.
But is the under-formed hippocampus losing our long-term memories, or are they never formed in the first place? Since childhood events can continue to affect our behaviour long after we’ve forgotten them, some psychologists think they must be lingering somewhere. “The memories are probably stored someplace that’s inaccessible now, but it’s very difficult to demonstrate that empirically,” says Fagen.
We should be very wary about what we do recall from that time, though – our childhood is probably full of false memories for events that never occurred.
Elizabeth Loftus, a psychologist at the University of California, Irvine, has devoted her career to the phenomenon. “People can pick up suggestions and begin to visualise them – they become like memories,” she says.