The fundamental difference between the quantum-mechanical method of describing the state of a system from the method of classical mechanics is that on the basis of quantum mechanics only the probability of detecting an object in a given region of space can be found. In principle, it is impossible to determine simultaneously the coordinates and velocity of a particle at any moment of time.
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.