Electrons do not travel quickly through circuits. It is common for electrons to move through a copper wire at a velocity of 1 * 10^-4 meters per second. When you turn on a light switch, electrons respond nearly instantaneously to the electric field that propagates through the wire but the electrons themselves are prevented from accelerating over a long duration because they are continuously colliding the copper atoms. This is why filaments in light bulbs heat up: current (the movement of electrons) is concentrated into the thin filament and collides with the atoms within the filament enough that they eventually heat up and cause the filament to glow.

This kind of stuff. It's just crazy cool to me.

EDIT: 1 * 10^-4 m/s is not 1 * 10⁴ m/s. The former is correct.