Replying to Worst Ski Advice

As I have continued skiing I've received all sorts of advice. Good, Bad, and even Weird. The biggest one that comes to mind was from a buddy of mine whose father is a classic old school skier. Long, straight skis, rear-entry boots, don't wear a helmet, etc. Now, the guy can rip for his age but I remember being told to lean back when skiing powder once when I was skiing with them. Keep in mind that I was on newer shaped, rockered, and wider skis. So what's the worst advice someone has told you?