Betcha don't know these clips... oh, you do? Well humor me anyway. The predecessor to the highly successful "One to Grow On" series, "Betcha Don't Know" featured NBC stars of the day involved in wacky skits that were designed to get across a fun fact, like why the sky is blue or why donuts have holes. They are similar in delivery to the ABC Fun Facts that would come along a few years later, only with less glasnost. These were produced by NBC and Children's Television Workshop, the Grand Poobahs of kids edu-tainment, and ran from some point in the 70s until the 1982-83 season.