Every single time I've listened to someone explain CRTs, they always gloss over an important part. "It has an electron gun that fires a beam of electrons at the back of the screen." Wait. What? What the heck is an electron gun? How do you fire electrons anywhere? What exactly does that mean? HOW does it fire electrons? An electron gun sounds as sci-fi as a photon torpedo. No one ever explains this part. They just assume I've encountered electron guns elsewhere in everyday life.