"Fastest" joke

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 it's 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 had been warmed over a time or two, and a buncha jalapeno and some chili peppers I never say 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 that damn light on. . . "