Thank you for your valuable review, Yeonju Kim 🙂 This course is structured so that the concepts learned in earlier chapters are applied in later ones, so I recommend taking the lessons in order. Since you have only completed about 7% of the course, you might feel differently once you see how the content connects in the following sections. If there are any specific parts you found difficult, please feel free to leave a message on the Q&A board, and I will provide a more detailed explanation. Thank you 🙂