A doctor had a regular habit of stopping off at a bar for a hazelnut daiquiri on his way home every evening. The bartender learned his habit and would always have the drink waiting at precisely 5:03 pm. One afternoon, as five o'clock approached, the bartender was dismayed to find that he was out of hazelnut extract. Thinking quickly, he threw together a daiquiri made with hickory nuts and set it on the bar. The doctor came in at his regular time, took one sip of the drink, and exclaimed, "This isn't a hazelnut daiquiri!"; "No, I'm sorry," replied the bartender, "It's a hickory daiquiri, Doc."