One of the nice things about HN is the wide age range of the participants. I have read interesting and thoughtful comments from people who said they were high school students all the way through to people a decade or more older than me (I'm sixty-seven).
Person born in 2000 here. My friends and colleagues at university generally don't know about HN.
Have told a few people about it but the only person I really converted into also becoming a regular reader is my dad. It's good because now whenever we see each other we have a lot of topics and stuff to discuss that we both read about here.