Hypocrisy is okay as long as that the person is giving good advice and isn't telling someone else off.
Like 'All of us' said about drug addicts, warning others about it, et cetera.
Also what if you learn something new, and change your mind? I would rather want to hear from someone that is open minded and will admit to being wrong then someone that will never change his mind, stick to his word that could be wrong, for fear that someone might think he doesn't know what he's talking about. (Really, who does know what they're talking about?)