Computers are not magical or mysterious. Their amazing abilities are built up from simple ideas. That’s what’s surprising. How did we arrive at today, with these devices in our pocket and a (nearly) global network connecting them, and with software running that allows it all to do so many useful and entertaining things?
Lady Ada, Countess of Lovelace wikipedia, was the first to get it. She understood, before any computers existed, that a machine with a few simple arithmetic abilities could do much more. (Notably, the men who were designing these calculating machines didn’t get it.) It would be about 100 years before the programmable computers she envisioned would be “invented”.