Why do Golf Courses have 18 holes?

Here's a little slice of golf history that you might enjoy. Why do Golf Courses have 18 holes? Not 20, or 10, or even a dozen?

During a discussion among the club's membership board at St. Andrews in 1858, a senior member pointed out that it takes exactly 18 shots to polish off a fifth of Scotch. By limiting himself to only one shot of Scotch per hole, the Scot figured a round of golf was finished when the Scotch ran out.

Now you know.