I agree. If it is so obvious, why do people like saying it?

Do they also go around repeating the sky is blue?

>The phrase appeared in print in the 1885 biography of the noted swindler Joseph "Hungry Joe" Lewis, "King of the Bunco Men". The author writes:

>>It was always a saying with Joe that there was a sucker born every minute, and all through his business career he acted on that basis, and generally found a good crop of them