Have you ever noticed that when you ask a question, you are less than satisfied with the answer? In a school that supposedly encourages the "questioning of assumptions", isn't it kind of important to get a straight answer out of them? Of course it is! But the reason they don't is that they simply don't know. The generic example is when you ask a question and the teacher responds by telling you everything he or she knows, rather than actually answering the question you asked. An example is:
Pupil: Why is VAT a regressive tax, sir, eh?
Teacher: Taxes are either progressive, proportional or regressive. A regressive tax is one where the percentage you pay gets less as your income increases.
You see he told you what a regressive tax was, but he didn't explain why, did he? This is the problem. This situation also exists when you ask if Tin is an ore and you get the complete history of cavemen. For example.