日夜颠倒

Just don't understand, why are there so many teenagers which live day as night and night as day. When the day break, tat's when they sleep. And when the nights fall, tat when they become active. Living this type of lifestyle, how to find a decent job? At least not in the current economy. This type of lifestyle is so unhealthy. Yet, knowing tat it is unhealthy, yet they lived this type of lifestyle. Just like, knowing that drugs and glue sniffing is back for them, yet they want to touch it. WHY? WHY?