Two gates, that's it

XOR behaves differently than the others. It's fine if it didn't fully click.

What matters is the pattern underneath it: every operation a computer does — comparing, adding, remembering — is just a combination of simple yes/no rules. The gates don't understand what they're doing. They just follow the rule they were built for.

You don't need to be able to reconstruct the circuit. You just need to see that it's possible — that something as human as addition can be built entirely from switches.

That's the idea worth keeping.