So there's these three blokes.
First one says "what do you think is the fastest thing in the world?".

The others think for a moment and the second bloke says "well I think the fastest thing in the world is electricity!"

The others of course ask "well why?".

He says "well as soon as you flip the switch the electricity turns on the light! It's instant!".

The first bloke who asked the question says "No, no, no it has to be talking! As soon as you say something to someone they hear it immediately!".

"Well" the third one says "you're both wrong.

The fastest thing in the world is diarrhea!".

The first two blokes look at each other and then at their friend confused. "well how is diarrhea possibly faster than electricity or talking!?"

"Well" he says "last night I had diarrhea and before I could turn on the lights or tell anyone I sh*t myself."