Juneteenth Awakening

Yesterday a friend who a high school social studies teacher, informed me that some of the high school students did not know the history of June 19. A few years ago, I was surprised that a few of my friends did not know the origin of this holiday. In my friends' defense, they are not from Texas. (They are also not African-American, however, some, but not I, see this as a reason for not knowing about an American holiday.) What defense does these African American high school students have? Were they not taught? Were they taught and did not retain the information? At the time they were taught, did they not value the significance? I am at a loss for an answer, but can add two cents to help. To anyone who needs it here is a link to some background information on Juneteenth. This is funny, not because Barney does not know about the Emacipation Proclamation, but funny because it is just another instance where he attempts to cover for his lack of knowledge.