The more time you spend tinkering with something, reading about it, watching YouTube videos or TED talks, the more knowledge you're going to build. If you're really lucky, you'll also learn and grow through the lessons life gives you as you simply get older.
At some point, people will come to see you as someone who knows about this thing, and ask you questions. They'll seek out your experience and what you can share with them so they might learn from you. This is valuable information they are willing to pay for, because learning from you saves them time.
You can teach anyone something new who's not quite as far along on the Knowledge-generating journey as you are - even though they might be older and more experienced in other things. (Of course you can coach them as well by not answering their question, but instead asking them new ones. Personally, if someone asks me a direct question I can answer, I do.)
What about the experts in your field, who have studied your thing all their lives? They might not ask you questions about content, but you can still show them what an inquisitive mind can do, and remind them what it's like from time-to-time to see their field of expertise with new eyes.
Best of all, as you work with the experts, your knowledge will keep growing, too.
Where can you bring teaching and coaching into your workplace or practice?