How do you know what questions to ask your lawyer? How do you know what info might be pertinent to helping your lawyer to give sound advice?

Let's say I were to ask for advice about X. Someone posts, "Oh, when I went through X, my lawyer advised me to do Y and I think it really helped." So, then when I talk to a lawyer I can ask about Y. I don't see how opening a dialog hurt anything?

How does a little extra knowledge lead to disaster? Note: I'm not talking about forgoing a lawyer's advice in favor of listening to an internet nutjob.

You seem to be advocating ignorance and/or blind faith lawyers. How do you recognize a bad lawyer if you don't make any effort to educate yourself?