It's surprising how apparently-useless information can give people a lot of insight. In "Guns, Germs, and Steel" and "Collapse" for instance, there were people

It's surprising how apparently-useless information can give people a lot of insight. In "Guns, Germs, and Steel" and "Collapse" for instance, there were people who dug through the latrines of ancient societies to determine that the early Easter Islanders' diet consisted of 25% porpoises; and that the Greenland Norse colony didn't eat any fish. Looking at the receipts of medicines bought in the court of Henry VIII allowed people to conclude fairly conclusively that he did not have syphilis. The thing is, it's really impossible to predict what information will and will not be a critical key to unlocking understanding of future generations. Just keeping it all, history, comments, and all, will be a huge boon to future historiographers trying to figure out what developing in the early 21st century was like.