All of this is fascinating.

The following happened in one of the classes for which I was the teaching assistant, so I had to offer help during office hours on an individual basis as well as run one large session pre-finals for everybody in a big auditorium.

So, that class was very quantitative. And in quantitative subjects, more so than in verbal, the sequence of knowledge acquisition matters a LOT.

Say, in a history class, if you missed a part, you can more or less still make sense of a later part because the "stories" are more disjoint. More stand-alone. But in a quant class or in a science class - think chemistry - if you miss the foundation, you have nothing to build upon. If I do not know the basics of organic chemistry, I will never understand the advance formulae with C and H written everywhere.

So, during the last session (Q&A),

1) a young woman asks me a Q in front of the class.

She qualifies the Q with all sorts of self-deprecating statements ("I am sorry", "I should have"), blushes, and, in a tentative voice...

ASKS A PERFECTLY REASONABLE QUESTION.

She had nothing to be sorry about - she did study on her own and during that studying happened on something that was not that well covered in the textbook.

2) twenty minutes later, a young man raises his hand. He puts on airs. He leans back in his seat and looks at me as if about to challenge me with the most difficult question.

AND ASKS SOMETHING THAT SHOWS THAT HE DID NOT UNDERSTAND THE FIRST LECTURE.

Now, the man was NOT dominant. The man was clearly not at ease with himself - it was more as if he could not just ask the question but felt obligated to put on airs.

And I saw it again and again - it is just that that example was the most striking.