While one man can discover a certain thing by himself, another is never able to understand it, even if taught by means of all possible expressions and metaphors, and during a long period; his mind can in no way grasp it, his capacity is insufficient for it.
MaimonidesEvery man should view himself as equally balanced: half good and half evil. Likewise, he should see the entire world as half good and half evil.... With a single good deed he will tip the scales for himself, and for the entire world, to the side of good.
Maimonides