I have never really had a problem with people believing what I have to say. Most of it is from what I've read, been taught or absorbed somewhere along the way, but I did inherit my Father's ability to confuse those people who are really gullible with some good ol' BS-ology if I don't know shit about the subject at hand. However...
I have never tried to bamboozle someone into believing some bullshit was the absolute truth - I usually come clean about my ignorance in short order.