I realize that there are already a lot of answers on this thread stating exactly the same thing that I am about to, but for the purpose of showing support and spreading awareness that a great many people share the opinion I'm going to post anyways.

If someone comes to you and asks you a question that you have the knowledge required to answer than it is your duty to answer them. This is how humanity improves itself, it is how knowledge is shared, and the basis for which foundations are set upon which new knowledge may grow.

Each and every one of us started out knowing nothing. Through a painstaking process of endless questions we have gained all of the knowledge that we now possess. For each of the questions we have asked, we were forced to turn to someone else who had the knowledge; and for each answer received we depended on that person to answer regardless of how simple or absurd it might have seemed to them.

I think we should all look back on the questions that we have been forced to ask, and imagine where we would be now if each of the people we asked had scorned us for our lack of knowing rather than answering us. How much knowledge would we now have? What if this process happened to every person you have ever met? Where would we be as a society?

It's easy to take what you have learned and leverage it over another for the sake of your own ego. It's a trap that everyone has fallen into from time to time. I know that I too have done so more than once. But wisdom tempers knowledge over time and I came to realize how childish and ridiculous my attitude was.

For the obligatory tl;dr: Think twice about looking down your nose at someone who asks you a simple question, for most questions you will ever ask will be simple to the one you ask it of.