I first discovered Little Thinker in 1980's. I was director of a university laboratory child preschool. The cassettes at that time were a miraculous benefit to our nap times Children who didn't nap would be mesmerized with imaginary world created by these adventures. They never grew tired of these. My children were raised on these and I am now wanting to purchase the entire MP3 set for their children. I, a child psychology diagnitician and psychotherapist give the highest rating to these wonderful adventures