Industriousness and conscientiousness are often at odds, because industriousness wants to pick the still sour fruit from the tree,while conscientiousness lets it hang there too long, until it falls and bruises.
Marriage was contrived for ordinary people, for people who are capable of neither great love nor great friendship, which is to say, for most people--but also for those exceptionally rare ones who are capable of love as well as of friendship.
Mathematics would certainly have not come into existence if one had known from the beginning that there was in nature no exactly straight line, no actual circle, no absolute magnitude.