Four old cowboys are having a discussion about what is the fastest thing in the world.
First cowboy says, "I believe it's thinking, 'cause when you prick your finger or touch a flame, the pain instantly becomes thought and hits the brain."
Second cowboy says, "Well, I think its blinking. When you blink and open your eyes again, you immediately see everything. Nothing is changed."
Third cowboy says, "Well, I think it's light, 'cause as soon as you press that light switch, you go from dark to instant light."
Fourth cowboy says, "Well, I think its the Mexican-two-step diarrhea."
All the others ask simultaneously, "Diarrhea? Why?"
Fourth cowboy says, "I'll explain it to you. I went across the border to a saloon last night and drank a buncha homemade Mexican tequila. On the way home from the saloon, I stopped off at Lupe's cafe and ate two helpings of her Mexican Special, which I suspect had been warmed over a time or two, and a buncha jalapenas and some chili peppers I never saw before."
First cowboy asks, "So, what's that got to do with speed or diarrhea?"
Fourth cowboy says, "Well, later on when I was in bed, I felt this fire and fierce rumbling in my belly, and before I could think, or blink, or turn on that goddamn light...."