My math teacher always used to say that there are three types of knowledge: what you know, what you know you don’t know, and what you don’t know you don’t know. That sounds mind-bending, but basically, “knowing that you don’t know” means that you’re aware that there’s a particular chunk of knowledge that you’re missing, but “not knowing that you don’t know” means that you’re completely oblivious that this chunk of knowledge even exists. For example, you might know that you don’t know calculus, and yet you’re aware that it exists—while some people are completely unaware that it’s even a thing, so they have no idea that there’s a gap in their mathematical knowledge. I like this perspective much better than the black-and-white idea that either know something or you don’t, and it’s why I never ridicule someone if they’re ignorant about something, even if it’s incredibly obvious to me. It’s also why I believe that there is no such thing as a stupid question—the very act of asking shows that you’re aware that you’re missing that information, and you’re consciously making the effort to fill the gap. Everyone has thousands of these knowledge gaps, but yours will never exactly match up with someone else’s. Everyone you meet will know something that you don’t. So when someone asks you a question, take it as an opportunity to expand their knowledge, and never laugh—or they’ll turn around and school you.