Electric current never flows, since an electric current is not a stuff. Electric current is a flow of something else. (Ask yourself this: what’s the stuff that flows in a river, is it “current” or is it called “water?”)
Wires are not full of current, they are full of charges that can move. Electric charge is real stuff; it can move around. But electric current is not stuff. If we decide to ignore “current,” and then examine the behavior of moving charges in great detail, we can burn off the clouds of fog that block our understanding of electronics.
An excellent explanation of electronics and transistors.
I’ve linked to their site before in the Unwise Microwave Oven Experiments post.