This body is made of three primary elements: mucus, bile and air. That is the Vedic version and Āyurvedic treatment. This body is a bag of mucus, bile and air. In old age the air circulation becomes disturbed—therefore old man becomes rheumatic, so many bodily ailments. So Bhāgavata says: "One who has accepted this combination of bile, mucus and air as self, he is an ass." Yes.
Actually, this is the fact. If we accept this combination of bile, mucus and air as myself . . . so intelligent person, a very great philosopher, very great scientist, does it mean that he's a combination of bile, mucus and air? No. This is the mistake. He's different from this bile or mucus or air. He's soul. And according to his karma, he's exhibiting, manifesting his talents.
So they do not understand this karma, the law of karma. Why we find so many different personalities? If it is a combination of bile, mucus and air, why they are not similar? So they do not cultivate this knowledge. Why there are dissimilarities? One man is born millionaire; another man is born, he cannot even have full meals twice a day, although he's struggling very hard. Why this discrimination? Why one is put into such favorable condition, why the other is not? So there is law of karma, the individuality.