Is there any instructional advice you’ve given over the years that you would, or have, later rescinded as your own knowledge progressed?

Question: I’ve a question for you sir, mostly out of curiosity regarding your own development over the years. We’ve all (I suppose) gotten various things fundamentally wrong at some point. Is there any instructional advice you’ve given over the years that you would, or have, later rescinded as your own knowledge progressed? If you’ve ever...