From The Histories, I.35:
The most difficult task I undertake as a history instructor is not preparing tests, lecturing, or even grading essays, but convincing my students that history is worth learning for its own sake—gratuitously, regardless of its "practical value." (There's a sinister phrase we're far too used to.) I don't know how well I have succeeded—the students who come out of my classes loving history usually loved it or were at least interested in it when they arrived—but one "practical" application that persuades at least some of them that history is worth studying is the concept of history as memory.
I introduce this idea at the beginning of every semester with another quotation from the classics, in this case Cicero:
To make this more explicit yet, here's the excerpt from Polybius's Histories above in its full context, in which Polybius explains one of his purposes for writing:
I record these things in the hope of benefiting my readers. There are two roads to reformation for mankind—one through misfortunes of their own, the other through those of others: the former is the most unmistakable, the latter the less painful. One should never therefore voluntarily choose the former, for it makes reformation a matter of great difficulty and danger; but we should always look out for the latter, for thereby we can without hurt to ourselves gain a clear view of the best course to pursue. It is this which forces us to consider that the knowledge gained from the study of true history is the best of all educations for practical life. For it is history, and history alone, which, without involving us in actual danger, will mature our judgment and prepare us to take right views, whatever may be the crisis or the posture of affairs.
I've been horribly burned and injured by things and, if my daughter and son, who haven't lived through anything like that yet, will listen to my stories, they don't have to. In the same way, if you can't find anything else to "get out of" history, realize that you can at least learn from others' mistakes and, with wisdom and judicious application to your own life and circumstances, avoid them. History, rightly studied, is acquired maturity.
A bit more practical, realistic, and—I think—moral and hopeful than the grim pragmatism of Santayana's axiom, which has become a modern cliche: "Those who cannot remember the past are condemned to repeat it."