If you love someone, don't hesitate to tell them. It could be anyone; your mother, father, friend. You could be the only one to remind them that they're important.
People wear masks, usually. You don't know what they're feeling. They may seem friendly but God knows what they're going through. They might be really unhappy. They're probably waiting for someone to recognise their worth.
Indeed, time is precious; it slips by like sand through your fingers. Maybe the warm body next to you today could be ice cold in a casket tomorrow. So if you care about someone, please, please tell them. An act of kindness could help so much.