Some time in the 1920s, the Conservative statesman F. E. Smith — Lord Birkenhead — gave a copy of the “Nicomachean Ethics” to his close friend Winston Churchill. He did so saying there were those who thought this was the greatest book of all time. Churchill returned it some weeks later, saying it was all very interesting, but he had already thought most of it out for himself. But it is the very genius of Aristotle — as it is of every great teacher — to make you think he is uncovering your own thought in his.
I can attest to this phenomenon in Aristotle and Kant. “They agree with me!” you think, before realizing they’re already several steps ahead of you.