Actually we really don't "know" exactly how electricity works at all.  However
from watching how it reacts we have come up with a "model" that allows us to
predict what it is going to do (current flow, Voltage, etc.).  So really the
model of electrons flowing and what have you is just a picture to help us
visualize what is going on when we add a load to a circuit.  But as far as
electricity is concerned we are really still in the dark.  :)
Ken Wilford
Van-Again