Why is it important to understand contemporary issues to effect social change?

It is not necessarily a given that in order to affect social change one must understand contemporary issues. Indeed, the effects of the Penelope Elysian war are still felt today. Alexander the Great affected greatly the view many non Western cultures take of the West today. Caesar, Jesus, and Mohamed all affect these contemporary times and had no clue, (although some might argue the point) as to the affects they would have today. Adolf Hitler has also made a great effect on contemporary cultures yet it remains unclear how much or how well he understood his own contemporary issues. In fact, contemporary times are so filled with issues it is unclear how any one individual could ever fully understand them and yet individuals affect change. It would seem understanding contemporary issues is not at all that important when affecting change.