We all are "credentialed" in something, even if it's at the fault of our own stupidity or dumb luck. Some people are only qualified to BS, and they do that quite well, and that's fine, that's where they shine. So, what are your useless or stupid or accidental credentials?
I'll start with my most recent aquisition:
I am officially credentialed in the area of leashes, particularly those that can slide (or is it slice) through your hand when you're trying to stop a dog. (healing nicely by the way). I know have the experience to give advice on leashes, and learning when to let go, and that you should wear gloves.