OMG!!! Thank you friends for my education.

I don't think they pretend. The reality is most don't take the time to learn, partly because they don't take the position seriously enough to be a true sales professional and partly because most customers don't put that much thought into the purchase, so the salesman isn't really required to be that educated on such matters.

The commercial sales guy is really the only salesman that MUST know and understand such things.