I agree with most of whats written here. I think there is a major point you're overlooking here. There is simply just too much information we're expected to know nowadays. You could argue that the amount of information we have to cram into our brains in such a short amount of time makes it very difficult to build good long term memories. High School and university curriculum's are forever expanding jamming more and more in the same period of time. Even in professional settings such as being a web developer or data scientist for example where new things are being invented by the second that then become the standard. At some point you'll need to offload long term memories to external sources. So while you may forget the actual content of what you need to know, you could for example remember what to google and the summary of the content you expect. Essentially our long term memories is transformed into pointers for external information banks. We only keep whats absolutely essential to perform our functions.