tell them that beginners should not be focusing on such questions, as it may serve to prolong progress in the early stages. emphasize the loooonnng road ahead, and focus on basics and principles.
While all of this is true, I think it's only natural for beginners to ask such questions, and they need to get satisfactory answers if they're going to invest the time the long road takes. Dismiss the question out of hand, and you may have just lost a student.
For this reason, and also for the OP's own training, I think it's important to have a level-appropriate answer. Show the student what to expect on the road from "brand new beginner who can't even stand right" to "competent martial artist."