Aristotle famously said 'A fool can ask more questions than a wise man can answer'.
The question is, is the question relevant and worthy of the time taken to answer it. If it is which of the 20 or so possible answers will you give?
Sadly in my teaching career the questions were always either very predictable and covered in the syllabus (99%)or so left field it was hard to work out where the questioner was coming from( eg why not take off down wind because the wind will help you along?).
For the questions that lay in the middle I usually worked out the answer on the way home in the car and learned from it. I wish there were more of these.
Either way don't be one of the insecure bluffers who gloss over everything they don't know and make out they know it all. This is so transparent and easy to spot.