Man is the only creature that consumes without producing. He does not give milk, he does not lay eggs, he is too weak to pull the plough, he cannot run fast enough to catch rabbits. Yet he is lord of all the animals.
Many people genuinely do not want to be saints, and it is probable that some who achieve or aspire to sainthood have never felt much temptation to be human beings.
Most people get a fair amount of fun out of their lives, but on balance life is suffering, and only the very young or the very foolish imagine otherwise.
Part of the reason for the ugliness of adults, in a child's eyes, is that the child is usually looking upwards, and few faces are at their best when seen from below.