磕 means ‘knock’. Why?
石 is ‘stone’; 去 means ‘going to'; 皿 is container like ‘cup' or ’plate‘ and so on.
So the whole character shows：One stone is flying to the plate! -----------Two hard things are going to hit each other. That is the real meaning of 磕.
Childish pure mindset can simplify your life which let you live in a light way！ Without man-made troubles you will work in high efficiency!