yes we must sleep min: 7 hours. If you loose one night sleep, your brain is not functioning properly.

One day loose: you will not know the difference.

Many days loose: you will feel the difference.

Nowadays, many people are having stress more or less. So I would like to suggest to relax as much as you can. Important is to control your mind not to get greedy, angry and ignorance. So you will be relaxed and feel good.