Acharya Prashant addresses the issue of overthinking and anxiety by explaining that the mind naturally seeks something to occupy itself. He suggests that if one does not have something truly important or worthy in life, the mind will inevitably be invaded by trivial, random thoughts. He compares these unimportant thoughts to germs or pathogens that are always present in the environment; one cannot eliminate them entirely but can develop an inner immunity. This immunity is built by identifying what is truly significant and becoming fully immersed in it.