This longitudinal study of robot programming in early childhood (ROPEC) was performed based on summative and formative assessments of the robotics program in kindergarten and year one of elementary school. The study aims to broaden our knowledge about children's understanding of programming, their confidence in ability to read and write programs, and their real capabilities of reading and explaining programs. In this study, we used a sample of 114 children (age 5-7 years) participating in the robotics program. Quantitative and qualitative data were collected from participant interviews. We added to the usual surveys a real evaluation by experts of children's capability to read and explain the code. Unique emphasis was put on being able to assess objective vs. subjective aspects of a ROPEC participant. Our findings revealed significant differences between objective beliefs and real capabilities of children that should be dealt with in any robot programming; however, the findings were very positive. The results of this study provide crucial evidence that participation in ROPEC contributes in reducing the gender gap in science and engineering. Girls are not less interested or capable than boys in reading, writing, or explaining the code and in important aspects are even better and more eager.