Why did he feel awkward when he read the articles he had written in the past?

This was due to the difference in writing style and writing skills, which caused the readers to feel a sense of familiarity and discomfort when reading their own works. Writing style and skills are gradually learned and developed in the process of writing. As time goes by, writing style and skills will also change. In the process of writing, you may have gone through many changes, improvements, and adjustments. These changes and adjustments may include changing the writing technique, modifying the language, adjusting the narrative rhythm, and so on. These changes and adjustments may cause your work to be different from the previous style and technique, so readers may feel uncomfortable. Reading one's own work was also a pleasure in the process of writing. By reading your own works, you can better understand your own thoughts and expressions, and you can also learn some new writing skills and language usage. Therefore, although readers may feel awkward, it is also a beneficial experience when reading their own works.