The train travel culture in different countries has specific etiquette that budget travelers should know.

India trains: the reservation system assigns specific seats/berths. Sitting in someone's reserved berth is expected to be resolved by showing your ticket and asking them to move — this is normal and nobody takes it personally. Middle berths fold down to provide lower berth space during the day; this is expected. Chai wallahs and snack vendors walk through trains constantly — their prices are low and the food is often good.

Japan trains: silence is the strong expectation. Phone calls in train carriages are frowned upon. Eating on local trains in cities is unusual though long-distance Shinkansen have trays and eating is normal. Quiet cars on Shinkansen are absolutely no food, no calls, no noise. The train will leave on time to the second — don't underestimate platform walk time.

Europe trains: more relaxed than Japan. Seat reservations are sometimes optional (on some services) and sometimes mandatory (TGV, ICE). The conductor will check tickets but the culture is relaxed. Long-distance trains often have dining cars.

India vs Japan contrast: Indian trains are social spaces where conversation with strangers is normal and expected. Japanese trains are private spaces in public where minimal interaction is the norm. Adjusting your expectations prevents uncomfortable cross-cultural misunderstandings.