You can now, if you choose, employ your present success to advantage, so as to keep what you have got and gain honour and reputation besides, and you can avoid the mistake of those who meet with an extraordinary piece of good fortune, and are led on by hope to grasp continually at something further, through having already succeeded without expecting it.
ThucydidesAnd it is certain that those who do not yield to their equals, who keep terms with their superiors, and are moderate towards their inferiors, on the whole succeed best.
ThucydidesFor if many ill-conceived plans have succeeded through the still greater lack of judgment of an opponent, many more, apparently well laid, have on the contrary ended in disgrace. The confidence with which we form our schemes is never completely justified in their execution; speculation is carried on in safety, but, when it comes to action, fear causes failure.
Thucydides