If a trip to Disneyland was a highlight of your childhood, thank Walt Disney. And if you can’t take your own child singing “Let it Go” one more time, you can blame Walt Disney. This hour, we’ll talk about arguably the most influential cultural and entrepreneurial figure of the 20th Century with Sarah Colt, director of American Experience: Walt Disney, which airs Sept. 14 and 15 on KERA-TV.