IWSG: The Most Hated Writing Rule

It's the first Insecure Writer's Support Group post of 2017. Thanks to Alex and his co-hosts for putting this event together every month. 

This month's question is: What writing rule do you wish you’d never heard?

Per the great Stephen King, "The road to hell is paved with adverbs." In other words, don't use adverbs. 

I happen to love adverbs. I think they're lovely. I like how they sound and how they slip delightfully from the tongue. They display beautifully on the page and contribute meaningfully to the story being told.  

I hate cutting them from my writing, but upon editing, I troll through the pages and spitefully kill the little darlings. (kill your darlings is from Stephen King's On Writing, which I highly recommend). 

And that is the writing rule I wish I'd never heard of. 

What's the writing rule you hate the most? Why?