This phrase uses the traditional concept of 'Kalyug' (the age of vice/darkness) to humorously describe the major generation gap and clash between:
* Hindi Teacher: The embodiment of traditional discipline, reverence for language, cultural values, and the Guru-Shishya tradition.
* Students of Kalyug: Modern, distracted, disrespectful, tech-obsessed students who treat the subject casually and challenge authority with modern slang and a lack of filter.
It's a common trope in Indian comedy and social media to highlight the challenges of teaching traditional subjects to the modern, rebellious generation.