Nature abhors a vacuum.

We always long for the forbidden things, and desire what is denied us.

Because just as arms have no force outside if there is no counsel within a house, study is vain and counsel useless that is not put to virtuous effect when the time calls.

Don't limp in front of the lame.

It is quite a common and vulgar thing among humans to understand, foresee, know and predict the troubles of others. But oh what a rare thing it is to predict, know, foresee and understand one's own troubles.

A man of good sense always believes what he is told, and what he finds written down.

Plain as a nose in a man's face.