Growing up in Oklahoma, and vacationing further south, I used to see those types of huge catfish and big carp, especially cruising around the boat docks. People cleaning fish always tossed the skin and bones over the side. I'd watch people fish for them sometimes, it could take them literally hours to reel one in. My father threw me into the water once in an effort to teach me to swim (he still denies it to this day), and I was totally traumatized. I was scared of the water, but even more afraid of being eaten alive by those things. LOL.
I did once have an enormous catfish or carp on my fishing line when I was about 14, it was probably a good thing I didn't catch it. I didn't even realize it was on my line, just noticed the line was slack and I couldn't seem to reel it in. Suddenly there was a huge swirl and a whitish belly rolling over in the water in front of me and the hook and my line popped free, one of the three pronged hooks was completely straightened. He'd been swimming towards me all that time while I was lost in a daydream. I don't know how the hook straightened when I didn't even pull on it, the whole episode was surreal. I practically had a huge fish hop into my lap without doing a thing.