You're right. In fact I think the ideal is even a step further up the abstract ladder: not every person in the street needs to be able to off-the-cuff explain t

You're right. In fact I think the ideal is even a step further up the abstract ladder: not every person in the street needs to be able to off-the-cuff explain the evidence for the earth being round. But they should know how to get the resources they would need to make that explanation.