Each person has their own sleep cycle
Sleep manifests itself differently for each person. People react differently to sleep as well as to all other life processes.
-Someone sleeps for 8 hours because that’s the only way they rest and don’t have nervousness and bad mood.

• For some people, 6 hours of sleep is enough, but occasionally later they sleep for 12 hours continuously
• Someone sleeps “in parts” or in one burst even in the midst of the loudest noise
  -Some people are awake for 72 hours, but later it takes a whole week to return to a “normal” state.
  A dream is a puzzle that science still cannot fully unravel. Scientists gave a definition of sleep which says “that sleep is the opposite of the state of wakefulness”. Scientists are cautious about one definition of sleep. If a person says “I slept…” – it looks simple… In fact, neither the heart, nor the nerves, nor the muscles, nor the lungs slept in the same way.
  Most of the muscles relax during sleep, but the sphincters are still awake
  A person’s heart rate decreases steadily and progressively, but the temperature increases to reach 37 °C when awake (which usually decreases by 5 am). Breathing follows a curve almost identical to the pulse. The brain sleeps in cycles (sleep changes several times during the night, i.e. alternating “deep sleep” with “light sleep”). If a person slept continuously throughout the night, then his organs slept, but each organ according to its own different rhythm.
  Each person has their own sleep cycle
  This cycle is largely due to habit. There is a widespread opinion that one hour of sleep before midnight is worth as much as 2 hours of sleep after midnight. This is true for people who have a habit of sleeping before midnight. This rule is not credible for people who sleep after midnight. The only difficult thing is to change sleeping habits.
  It is considered that an adult needs at least 8 hours of sleep in 24 hours
  This number is subject to individual variations in ordinary life (because some people need 10 hours of sleep or more. Some studies say that it is good to maintain a ratio of one third of sleep and two thirds of wakefulness.
  It is very likely that man’s uninterrupted sleep is a matter of social order and convenience. Man adapts to his lifestyle, although sometimes it takes some effort to harmonize sleep and wakefulness. The main causes of insomnia are coffee, tobacco, alcohol in small doses, large meals and hunger. However, there are people who respect all of the above but have insomnia. Then it can rightly be said that insomnia is a habit (because a person can easily get used to sleeping or not sleeping).
  A person needs to learn to sleep to get rid of insomnia
  One should first know one’s own dream. There are various bedtime tricks (for falling asleep). Some people like a warm bath while others like a warm drink. Science has tested the value of monotonous stimuli (there are people who are lulled to sleep by the beat of a metronome just as babies are lulled to sleep by the rocking of a cradle).
  The reasons for insomnia are sometimes insignificant. For example, an overly soft pillow or mattress, sleeping near an open window, too many blankets, etc. One should still try to solve the insomnia or seek the advice of a specialist/doctor. The causes of insomnia are sometimes organic in nature.
  Small tips for a good sleep:

1. It is better to sleep on a hard mattress, as this avoids accidental deformations of the spinal column.
2. A person should not be constricted by anything around the waist (some sleeping shirts have a belt that needs to be taken off before going to bed, etc.). Pants or pajama bottoms should also be appropriate.
3. The evening meal should be light (no coffee and too much alcohol).
4. Try to remove negative thoughts.
5. It is not advisable to sleep immediately after physical (or intellectual) work. Spend at least a few minutes in some monotonous work (for example, brushing your hair, flipping through the press, reading, etc.). Breathe deeply next to an open window, take a short walk and take a warm shower. A person should do the activity that suits him best.
6. Sleep is the only way (so far) for a person to completely relax and rest from all the daily efforts. A rested body finds all the answers to life’s questions (doubts) more easily in the morning, and a renewed spirit finds new solutions more easily.