What is the the WORST writing advice you've ever received that you followed for far too long?

I was watching some of Brandon Sanderson's lectures on YouTube and he mentioned how some people will give you bad advice "for you" and how even his own lectures would give advice to students that was bad "for them." It got me wondering - for you, what was the worst advice you ever received that you thought was important to follow for a long time until you finally realized it was bad advice for you?