The human body, which is mostly liquid, is a good conductor. Only a significant resistance of the hardened skin of the hands prevents the flow of a high current through the body. Therefore, at low voltages of several volts, a current of a fraction of a milliampere flows through us, which we do not even feel. But already starting with a voltage of U = 36 V, an increased current strength can cause a noticeable biological effect, and a current with a strength of more than I = 100 mA, as a rule, is fatal.
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.