It hits me every time I step off the plane: the sudden chill of full-blast air con and the distinct scent of orchid-tea fragrance diffuser. Airports can feel nondescript, but arriving at Changi – both today and long before the Covid-19 pandemic – is a uniquely Singaporean experience. On the way to passport control, walking through the perfumed air, you'll see immaculately kempt green walls and tidy water features, teams of janitorial staff (in both human and robot form) and high-tech washrooms with interactive feedback screens.