Maybe it's old and well known, but somebody asked, so here it goes:

A shepherd is quietly grazing his sheep on the fresh village pastures.

Suddenly a shiny new car stops by. A cool guy, very well dressed hops out and asks him: "Good man, If I guess exactly how many sheep you have, can I win one?"

The shepherd, puzzled, accepts.

The cool guy, opens his laptop, download a satellite picture of the area, run a NASA algorithm for image recognition and in few seconds answers "you have 1342 sheep"

"Wooow" says the shepherd "you won, take one"

The cool guy is about to live when the shepherd approaches him:

"Ehi, Young man, I bet all my flock against your car that I can guess what is your job"

The cool guy, (he likes to bet after all) accepts.

"You are a consultant" says the shepherd.
"WTF! how did you even..."

"Well, easy" says the shepherd "you came out of nowhere, well dressed and smart looking, you answered a question nobody asked you, you told me something I already knew, you want to be payed for that and in addition, you don't understand shit about my business."

"Now", adds quietly the shepherd "please, give me back my dog"

(for @LOLjustCoding)