Sure enough, it was just as I had dreaded, he started to climb the tree-"
"What the Bull?"
"Of course- who else?"
"But a bull can't climb a tree."
"He can't can he? Since you know so much about it, did you ever see a bull try?"
"No! I never dreamt of such a thing."
Well, then, what is the use of your talking that way, then? Because you never saw a thing done, is that any reason why it can't be done?

Autor: Mark Twain