Tell me what it really means to be South Asian

I grew up surrounded by Indians who would automatically speak to me in Hindi. Why was I expected to know Hindi? I felt immense guilt and would apologetically explain that I speak Tamil, a South Indian language. My immigrant parents raised me to be fluent in reading and writing Tamil. Yet I was ashamed for not knowing popular Bollywood films or the “quintessential” Indian music because I felt that was crucial to being perceived as culturally Indian.