In plain words
One who strays from the path in the forest finds it very hard indeed to reach his own place. So merely by gaining an acquaintance with śāstra as śāstra, your heart does not become pure. If your heart is to become pure,
bhajagōvindaṃ bhajagōvindaṃ gōvindaṃ bhaja mūḍhamatē, samprāptē sannihitē kālē nahi nahi rakṣati ḍukṛñ karaṇē.
In olden times people, pure of heart and free of selfishness, would now and then see the elders, listen to their teachings, practise them and be saved. But as time went by and the ages changed, man's powers and resolves came to show themselves under selfishness and self-interest. Whatever he does, it is selfishness itself. People sunk in this selfishness have had no chance to see the elders. Even if by some good fortune they get one, they do not listen to their teachings. Even if, as their lot allows, they hear their teachings, they do not practise them. That is why man, however many pleasures he may have within, cannot gain Śānti. Without Śānti, where is happiness? So Śānti is the chief principle for man. Such Śānti comes to us only when one recognises oneself; with mere sādhana, of however many kinds, a passing satisfaction may arise. The desires of man today have no limit at all. Desires beyond measure go on growing still more. This is the very teaching Vāmana gave: ‘Bali! For this disease called desire, contentment is the only medicine. Without contentment man cannot reach Ānanda. So sacrifice is most needed for man. However long it has been, however many years one has lived, desires still go on growing beyond measure, but one does not try to lessen them even a little.
To this very thing Śaṅkara gave a new name, ‘tṛṣṇā’. Tṛṣṇā means thirst. When we are thirsty, we may drink water. When is this thirst quenched? When we drink, it is quenched. Thirst keeps coming back again. As long as this life lasts, thirst coming and water being drunk, this goes on happening. This thirst is a strong chain. These very chains bind man fast. Even iron may rust in time and lose its strength. But the strength of tṛṣṇā goes on growing day by day. It cannot lessen.
It is not right, not right, this thirst for wealth, O man; with a good mind give up your desires. Is not wealth the very fruit of karma? Find contentment in what you have. Hari Govindā, Hari Govindā, say Hari Govindā, you dullard!