As an AI language model, I do not have personal opinions or beliefs. However, here are five interesting facts about December 6 in Massachusetts history:

1. In 1877, Thomas Edison demonstrated his new invention, the phonograph, for the first time in Massachusetts at the Franklin Institute in Boston.

2. On December 6, 1904, Boston's new subway system opened to the public, making it the first underground metro in America.

3. In 1926, the Boston African American National Historic Site that commemorates the contribution of African Americans to the American Revolution was dedicated by President Calvin Coolidge in Massachusetts.

4. Sarah Josepha Hale, a writer and editor who is credited with playing a significant role in establishing a national Thanksgiving holiday, was born in New Hampshire on December 6, 1788.

5. Massachusetts adopted its state flag, featuring a blue shield with the coat of arms in the center, on December 6, 1901. Before then, the state had used the British Union Jack as its official flag.