The fastest thing in existence.
Three friends, sitting around a table, enjoying a little time together over a couple of drinks.
At some point, one says:
“The fastest thing there is? Thought. Only takes a moment and there it is: an idea.”
“Nope. Electricity is the fastest thing there is; a flick of a switch and bam! there it is.”
”You’re both wrong.”
The third man muttered over the rim of his glass. His two friends were looking at him, expectingly, as he set back down his glass.
”If it isn’t thought, if it isn’t electricity, then what is it?”
”Diarrhoea. The other night, I didn’t had time to think nor turn on the light: I just crapped myself.”