History is very hard to study as we can't get the point of view of everyone in a given situation; that's why people say "history is written by the winners", you can't really know from which side this history is told and how it could have affected its objectivity. That's what makes History study a job itself.
But you're right on the point that everything that happend today often happened in the past and we can learn from History about it ! It just needs to be done with a lot of relativity and objectivity.
(But this is just my opinion :-P )