You, of course, know that for a fact. You are capable of pronouncing such assessments regarding an issue that probably (or not) happened before you were born. You are quite the intelligence operative. I’m impressed.
“You, of course, know that for a fact.”
Yes, because it is a fact. Need to know is determined on an individual basis. That is a fact, not an opinion. If Einstein was determined to have a need to know, it would not automatically extend to his secretary. There is no speculation involved in that assessment.