My questions are mostly so they start thinking about why they're really asking, since usually this is simply infatuation and the long term hasn't been considered. UX Design is currently in some ways the cute new kid getting lots of attention in class at school and everyone is wondering how to get a little closer. So I don't really care what their answer is, because the curiosity is a good thing and I want everyone to know more about design. But just as importantly, I want people to know why they pursue a certain thing. Life seems to work best when your pursuits have passion behind them.
The next step is to give them my favorite getting-acquainted-with-the-heart-of-design reading material, two books and an article that focus on how design is for enabling and delighting people as they try to make life happen. These three cover or touch on most of the things I still think about daily as I pursue my second decade of design. Maybe they'll help you, too.
Now, sometimes I get the response that they've been copying Microsoft or Apple design, or using designs they've found on other websites. I reply that this is good. Emulation is a good way to learn design technique. To really understand how to design for other people, though, requires learning how to create design solutions by identifying, analyzing, and solving problems before you apply design techniques. If that’s the desired direction, one should start by reading the above and see what is inspiring. If the passion to make things better through creation comes to life, then a whole world of design knowledge and skill to absorb will open up in front of you.