the feeling of a static electric shock is caused by the stimulation of nerves as the neutralizing current flows through the human body. due to the presence of much water in the body, the charge is generally not enough to cause a dangerously high current. lightning is also an example of static discharge. a cloud gets a very huge charge by clashing with other clouds. it gives off the excess charge to the ground. but this huge charge never occurs in the human's surroundings naturally, unless he is struck by the lightning.