Usually in the stage of fatigue, active rest does not help. Need a passive rest, sleep. However, with strong physical exertion, the transition to rest should be gradual. First you need to walk around a bit, wait until the pulse and breathing calm down, and then do quiet work or even lie down to rest. After completing the mental work, it is also useful to take a leisurely walk in the fresh air and only then go to bed.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.