Can someone guess my keys?

Even though everyone can see your public key, they can't figure out your private key from it. It's like the magic box is really good at making puzzles that are easy to solve one way (to check if the private key matches), but super hard to solve the other way (to figure out the private key from the public key).

So, your private key is your secret code that only you know, and your public key is like a puzzle that everyone can see, but only you can solve because you have the secret key.