"What would happen if I were to stick my hand in it?"
If you've ever stuck your hand out the window of a moving car, then you already have experience with this force.
I don't think one would want to stick one's hand in there.
"And for some reason I decided to stick my hand out the window, into the water," he continued.
I stick my hand in the water to catch you.
Even as the doors close, he can stick his hand in at the last second.
Too long for him, so he stuck his right hand up and tried to catch it.
"How long has it been since you stuck your hand in there?"
"I don't want to stick my hand in where I'm going to get it bit off."
One day, he stuck his hand in the wrong place and got shocked.