I think the most important thing for young people is that they're not trapped in the past. And human progress is driven by looking at a problem with fresh eyes, with new eyes. [...] And that's the power of young people, is asking why. Little kids, they naturally do that, right? When you talk to a four-year-old or a five-year-old, six-year-old, you tell them to do something -- "Why?" "Why?" And sometimes, as parents, we try to say, "because I told you so." And we don't want to talk about it, right? But that impulse to ask why is actually what drives human progress. [...] Vision is important, but then you also have to have the persistence to keep working to make progress. And I always tell young people to have big dreams, but then also be willing to work for those dreams. It's not going to come right away.