One of the most common phrases I read in book or course reviews is ‘nothing new here’ or ‘I know this already’. If you find yourself saying that the question is this: when are the last three times you applied this knowledge? Assuming that you think the piece of information is correct when did you actually use it? If you don’t remember you might as well stop looking for new information. After all, if you don’t use the information you supposedly ‘know’ then reading it is entertaining yourself not educating yourself. If you feel offended don’t be: this is a reminder for myself as well.