"I think the doctors have got it wrong about smoking."
Reminds me of that funny Woody Allen movie (way, way back, when he made funny movies) where the doctors were siting around and smoking and eating fatty foods. They were laughing and saying that they could remember when people thought that such activities were bad for your health, when in fact they now knew (then, in the movie's future time setting) that they were in fact GOOD for your health.
As for mistakes, yeah, read the directions if they make any sense. They don't always do that. I'm actually a big fan of screwing up royally and understanding what went wrong so that we understand the process, or just to see what happens. Many scientific advances came from people just screwing around and doing what they shouldn't do. But if course, don't complain if things go awry. That's part of the bargain.