Okay, I've got two.
First, when I first got my tank and was still very new and stupid to how to raise fish, and more importantly, keep them alive, I was in my local Petsmart. The young girl working in the fish section told me that cycling a tank was a myth, and just a way for the mfrs to make money selling products and chemicals. She didn't believe in it and told me to just fill my tank with water, turn on the filter, add conditioner and chemicals to set the ph and block the ammonia, and to start adding fish right away! Just make sure to only add two at a time every two days and I'd be fine. And if any of them died, to bring them back and they'd exchange them for the 14 day period they offer on each fish.

Needless to say I didn't know hardly anything about fish back then, but I still knew enough to know she was an idiot.
I also feel I must add that I never saw that girl in there again, and since then I've found that a couple in there that really DO know what they are doing. So there are some out there at the Petsmarts that know what they are doing, just very few!
Second one was from last night. I was back in Petsmart again checking out their stock and overheard a lady come in and ask the girl working there what their most 'hardy' fish was. When asked what she was looking for, what size tank, etc.. The lady explained that she wanted to buy her son-in-law a Xmas gift. She had no idea how to keep fish, but he did and she wanted to suprise him. She started to explain how she saw a tv show at some time about how fish were frozen in ice, then came back once thawed??:WTF: So she was wanting to get some to give for a present and was planning on freezing them so her son could have them on Xmas morning???? I REALLY wish I could've taken a picture of the look on the employees face, it was classic. I couldn't help it and started laughing. Thankfully the employee, very diplomatically I might add, explained that th fish wouldn't survive and she would be better off buying him a gift certificate. I had to walk off at that point cause the customer was scowling at me cause I was still laughing.