This aphorism means that “injuries” (which can be related to problems, disagreements, a harmful or painful situation) can be easily disappear just as dust do with a simple puff of air). On the other hand, the benefits you get by experiencing a conflict or a worrying situation will last for ever in the same way a craftsman caves into marble. All in all, people should look at the good side of things rather than the negative ones.
The last sentence (The Land of Horses) shows correct verb agreement. If it helps, change your subject to its pronoun - for example: Lost Cities describe the discoveries of many ancient civilizations. Lost Cities is the subject, a novel. IT DESCRIBES the discoveries of many ancient civilizations.
It is important because by assuming your partners mean well, you are allowing them to show their potential, and do their best. Whereas reacting negatively would make your partners feel bad, and they may not want to contribute anything to the project at all.
