This question bothers me so much that once I get to be a good enough programmer I actually want to build a website that will connect adult beginners with each other so that maximum learning can happen with minimal embarrassment and no interaction with children. A system where you can trade tutoring ("I'll teach you the violin if you'll teach me painting") or simply pay for classes, with some way to rate and view the quality of each person's teaching would be useful.

As long as there is no larger system like that, I'd suggest that your best bet is to find a friend or acquaintance who is good at whatever you want to learn and offer them something they want but wouldn't ask for, whether it's money or a favor. That way, you get to learn things at a personalized pace while building a friendship.