For Cheng, there is nothing strange about the life of the puppeteer that appears in Blue Cha Cha. In fact, his father was a traveling salesman of medicines, and the joys and sorrows of people in the lower social strata are what he saw every day during his childhood in Ilan's Luotung.
事實上，他的父親以前便是「跑江湖」的賣藥人，而他作品裡那底層生活的喜怒哀樂，更是他童年時在宜蘭羅東老家周遭，每天親眼目睹的人生百態。