The Syrians forgot how to make Damascus steel for a variety of reasons. One reason is that the production process for Damascus steel was a closely guarded secret and was passed down through generations of sword-smiths. However, as the demand for swords decreased with the advent of more modern weapons, the knowledge and skills required to make Damascus steel began to fade. Additionally, the political instability and wars in the region disrupted the traditional craft and artisan communities, many of which were scattered, destroyed or in decline. Furthermore, the raw materials needed to make Damascus steel such as specific types of iron ore were not easily accessible and the technology for producing Damascus steel was complex.
Another reason was that the method for making Damascus steel was lost during the decline of the Islamic Golden Age. The Islamic Golden Age was a period of great prosperity and cultural achievements in the Islamic world, which lasted from the 8th to the 13th century. During this period, sword-smiths in the Near East, particularly in the city of Damascus, developed the techniques for making Damascus steel. However, as the Golden Age came to an end, the knowledge and skills required to make Damascus steel were lost.
In summary, the process of creating Damascus steel was lost due to a combination of factors including the decline of sword-smithing as a profession, lack of access to raw materials, lack of political stability, and disappearance of traditional craft communities and finally lost in the decline of Islamic Golden age.