My first experience with a Snapping Turtle was when I walked in on an Alligator Snapper at my favorite hole in the local creek when I was 7 or 8. As soon as I saw it, it did a 180 and bee-lined for the water, just a few feet away. It did this in a flash!
10 minutes later, it took my bait. I thought I was snagged, then, managed to see it when I lifted it up off the bottom a bit. I dropped my rod to point straight at it, and pulled back until the line popped. I ran like the dickens. It took me over a month to work up the courage to fish that hole again.