"Stupid people" joke

Stupid people should have to wear signs that just say, "I'm Stupid". That way you wouldn't rely on them, would you? You wouldn't ask them anything. It would be like, "Excuse me...oops, never mind. I didn't see your sign."
It's like before my wife and I moved. Our house was full of boxes and there was a U-Haul truck in our driveway. My friend comes over and says, "Hey, you moving?"
"Nope. We just pack our stuff up once or twice a week to see how many boxes it takes. Here's your sign."
A couple of months ago I went fishing with a buddy of mine, we pulled his boat into the dock, I lifted up this big 'ol stringer of bass and this idiot on the dock goes, "Hey, y'all catch all them fish?"
"Nope. Talked 'em into giving up. Here's your sign."
I was watching one of those animal shows on the Discovery Channel. There was a guy inventing a shark bite suit. And there's only one way to test it. "Alright Jimmy, you got that shark suit on, it looks good. They want you to jump into this pool of sharks and you tell us if it hurts when they bite you."
"Well, all right but hold my sign. I don't wanna lose it.
Last time I had a flat tire, I pulled my truck into one of those side-of-the-road gas stations. The attendant walks out, looks at my truck, looks at me, and I SWEAR he said, "Tire go flat?"
I couldn't resist. I said, "Nope. I was driving around and those other three just swelled right up on me. Here's your sign."
We were trying to sell our car about a year ago. A guy came over to the house and drove the car around for about 45 minutes. We get back to the house, he gets out of the car, reaches down and grabs the exhaust pipe, then goes, "Darn that's hot!"
See? If he'd been wearing his sign, I could have stopped him.
I learned to drive an 18 wheeler in my days of adventure. Wouldn't ya know I misjudged the height of a bridge. The truck got stuck and I couldn't get it out no matter how I tried. I radioed in for help and eventually a local cop shows up to take the report. He went through his basic questioning... ok... no problem.
I thought sure he was clear of needing a sign... until he asked "So... is your truck stuck?"
I couldn't help myself! I looked at him looked back at the rig and then back to him and said "No, I'm delivering' a bridge... here's your sign."