Juggling is a perfect example. However, most non-jugglers don't offer advice to someone, who say, is struggling with a new move or having difficulty earning a living at juggling.
Not writers, though. Holy Hannah!
All you have to do is mention that you're 1 (querying for an agent) 2 (trying to finish a book) or 3 (looking for a new way to promote your book to improve sales) and the knowledge that spouts forth from the milkman to the barista will knock you off your feet.
And what do I do with this advice?
I usually smile and say, "Good idea. I'll think about that." Because where on earth do you start to explain why their advice is so asinine?
Here are a few pearls of wisdom I've heard from non-writers...
1. "Why don't you write a screenplay instead?"
2. "Don't lose faith, JK Rowling had twelve rejections before she was published."
3. "Erotica is hot now. Write that instead."
4. "Put a vampire in it."
5. "Send a copy to Ellen, maybe she'll invite you on the show."
6. "Open your own publishing company then you can publish all your own books."
7. "Can't you buy an agent?"
8. "It can't be that hard. My sister-in-law wrote a book and sold it to Harlequin. She paid off her house in the first six months...and my sister-in-law isn't that smart."
9. "Books aren't really selling these days. Why don't you send in some funny jokes for Reader's Digest?"
10. "People are hooked on Netflix. Write something kind of like Game of Thrones or The Walking Dead."
Any of these sound familiar? Do you have any to share?