Al Mualim's words in the Piece Of Eden
I applied my heart to know wisdom, and to know madness and folly. I perceived that this also was a chasing after wind. For in much wisdom... is much grief. And he that increaseth knowledge... increaseth sorrow. Destroy it! Destroy it as you said you would! I... I can't! Altaïr. Yes... you can Altaïr... but you won't.