My boyfriend always likes to use ignorance against me. How should I answer him?

Think he's naive

But it is also a sign of his lack of self-confidence.

You can try asking him simple questions first in the future.

He must have known and answered.

You said you praised him, and you said you were stupid. Why don't you know this?

Then he will gradually have confidence.

He will find a way to know your problem if he doesn't know it in the future.

Really try.