Doctor goes to a bar

A doctor made it his regular habit to stop off at a bar for a hazelnut daiquiri on his way home. The bartender knew of his habit, and would always have the drink waiting at precisely 5:03 p.m.

One afternoon, as the end of the work day 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.