Lack of Sleep

Lack of sleep and irregular sleep period are defined as staying up late. How often did you stay up late or stay up over night?How many hours do you sleep every night? Many people stay up late not because they could not sleep,but because they keep browsing the internet and using smart devices ,trying to call it a day as late as possible,even bed time as already come quite a while ago. Is that you ,why on the earth can’t we get rid of staying up later as if we are avenging the quickly past time?