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The Peanuts character Schroeder was a massive fan of Beethoven, and over the years Charles Schulz had shown him celebrating Beethoven's birthday on December 17. In 1967, however, he obviously was busy or something because he forgot. Poor Schroeder.

Also, Snoopy is apparently on his way to the 1968 Winter Olympics in Grenoble, France. He never made it there, however, as when he originally set out he didn't realize he had no way of crossing the ocean.