Why the rainy season is there? Can you answer why the rainy season is there? Why it is raining? These are periodical changes. Just like there is summer season, winter season, rainy season. Similarly, this material world is subjected to the seasons, or changes. It is called jagat. Jagat means which is changing. But we do not like this changing, because we are eternal. We have been put into this condition, changing condition; therefore we are not happy.
So this Kṛṣṇa consciousness movement means to get ourselves out of this changing condition to the eternal condition. It is very, I mean to say, what is called, intelligent question. (break) Why there is Kali-yuga? Kali-yuga means these ages have change. Just like the same way as there is summer season; after summer season, there is rainy season; after rainy season there is winter season. Similarly, there are four yugas, namely Satya-yuga, Tretā-yuga, Dvāpara-yuga and Kali-yuga. Satya-yuga means perfect age. Then Tretā-yuga—one-fourth less of perfection. And then Dvāpara-yuga—three-fourth, er, yes, half less; and Kali-yuga—three-fourth less. Three-fourth bad elements and one-fourth good elements. That is also very rare.