Everyone is ignorant on many levels. “Ignorance” is simply not knowing something or, at least, not knowing something well. There is no shame in that. Nobody can know everything.

Stupidity is different. The most intelligent and informed folks can be (and often are)  “stupid”.

When someone laughs at another person’s  “stupid” question, they are laughing at somebody who is trying to become less ignorant. How stupid is that?

Throw politics into the mix. It is often the case when a voter casts his/her ballot while ignorant of the policy or candidate concerned. That is stupidity in action.