A duck walks into a bar. He goes up to the bartender and says, "Hey buddy. Got any grapes?" The bartender says, "Grapes? No, we don't have any grapes. This is a bar. Get lost, would ya?" The duck says, "Okay, thanks," and walks out.
Next day, same exact time, the duck walks into the bar. He goes up to the bartender and says, "Hey buddy. Got any grapes?" The bartender says, "Look, I told ya once, we don't have any grapes. Now get the hell out of my bar." The duck says, "Okay, thanks," and walks out.
Next day, same time, the duck walks into the bar. He goes up to the bartender and says, "Hey buddy. Got any grapes?" The bartender says, "Look, pal, I'm not repeating myself again. No grapes! You come in here asking for grapes again, and I'm gonna nail your bill to this bar!" The duck says, "Okay, thanks," and walks out.
Next day, same time, the duck walks into the bar, goes up to the bartender. "Hey buddy. You... uh... you got any nails?" Bartender looks under the bar, says, "Nails? No, why the hell would I have nails?" Duck says, "In that case, got any grapes?"