History is -- or should be -- a lesson in appreciation. History helps us keep a sense of proportion.
History teaches that there is no such thing as a self-made man or woman, that we are all shaped by the influences of others, including so many we've never seen because they are back there in history.
History teaches that nothing happens in isolation, or without cause and effect, and that nothing ever had to happen as it did.
History teaches tolerance, and the value of common sense, and as Voltaire (and who knows how many others) observed, common sense is anything but common.
Read all of David McCullough's 2003 Jefferson Lecture.